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COLLEGE  OF 

PHYSICIANS  AND  SURGEONS 

LIBRARY 


Gift  of 
Dr.  0.  S.  Strong 


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Digitized  by  the  Internet  Archive 

in  2010  with  funding  from 
Columbia  University  Libraries 


http://www.archive.org/details/essentialsofhist1885shar 


THE    ESSENTIALS 


OF 


HISTOLOGY 


DESCRIPTIVE   AND   PRACTICAL 


FOR      THE      USE      OF     STUDENTS 


BY 


E   A.  SCHAFER,   F.R.S. 

JODRELL  PROFESSOR  OF  PHYSIOLOGY  IX  UNIVERSITY  COLLEGE,  LONDON 
EDITOR  OF  THE  HISTOLOGICAL  PORTION  OF  QUAIN'S  "ANATOMY' 


PHILADELPHIA 
LEA     BROTHERS     &     CO. 

1885 


PEEFACE. 


This  Book  is  written  with  the  object  of  supplying  the  student  with 
directions  for  the  microscopical  examination  of  the  tissues.  At  the 
same  time  it  is  intended  to  serve  as  an  Elementary  Textbook  of 
Histology,  comprising  all  the  essential  facts  of  the  science,  but  omit- 
ting unimportant  details,  the  discussion  of  which  is  only  calculated  to 
confuse  the  learner.  For  a  similar  reason  references  to  authorities 
have  also  been  omitted.  Most  of  the  illustrations  are  taken  from  the 
second  volume  of  Quain's  Anatomy,  ninth  edition,  where  their  author- 
ship will  be  found  acknowledged.  Of  the  remainder,  those  which 
have  been  selected  from  other  authors  are  duly  indicated ;  the  rest 
have  either  been  drawn  expressly  for  this  work,  or  have  been  trans- 
ferred to  it  from  the  author's  '  Course  of  Practical  Histology.' 

4 

For  conveniently  accompanying  the  work  of  a  class  of  medical 
students,  the  book  is  divided  into  forty-two  lessons.  Each  of  these 
may  be  supposed  to  occupy  a  class  from  one  to  three  hours,  according 
to  the  extent  to  which  the  preparations  are  made  beforehand  by  the 
teacher  or  are  prepared  during  the  lesson  by  the  students.  A  few  of 
the  preparations — e.g.  some  of  those  of  the  sense-organs — cannot  well 
be  made  in  a  class,  but  it  has  been  thought  advisable  not  to  injure  the 
completeness  of  the  work  by  omitting  mention  of  them. 


w  PREFACE 

Only  those  methods  are  recommended  upon  which  long  experience 
has  proved  that  full  dependence  can  he  placed,  but  the  directions  given 
are  for  the  most  part  capable  of  easy  verbal  modification  in  accordance 
with  the  ideas  or  experience  of  different  teachers. 

For  other  processes  and  more  minute  details  than  could  suitably 
be  given  here  the  student  is  referred  to  manuals  which  are  devoted  to 
practical  work,  such  as  the  '  Practical  Physiology  '  of  Prof.  Foster  and 
Mr.  Langley,  the  '  Practical  Histology '  of  Prof.  Eutherford,  the 
'  Textbook  of  Practical  Histology '  of  Prof.  Stirling,  and  the  author's 
'  Course  of  Practical  Histology.' 


CONTENTS. 


INTRODUCTORY. 

PAGE 
ENUMERATION   OF   THE   TISSUES — GENERAL   STRUCTURE   OF  ANIMAL   CELLS  1 


LESSON    I. 

USE   OF  THE   MICROSCOPE — EXAMINATION    OF   COMMON   OBJECTS   .  .  .  4 

LESSON   II. 

STUDY   OF   THE   HUMAN   BLOOD-CORPUSCLES 7 

LESSON    III. 

ACTION   OF   REAGENTS   UPON   THE   HUMAN   BLOOD-CORPUSCLES        ...        12 

LESSON    IV. 

STUDY   OF   THE   BLOOD-CORPUSCLES   OF   AMPHIBIA 14 

LESSON   V. 

THE   AMG5B0ID   PHENOMENA   OF   THE    COLOURLESS   BLOOD-CORPUSCLES  .        16 

LESSON   VI. 

EPITHELIUM 19 

LESSON   VII. 

COLUMNAR   AND   CILIATED   EPITHELIUM   AND    TRANSITIONAL   EPITHELIUM       .        23 

a 


vi  CONTENTS 

LESSON"    VIII. 

PAGE 

STUDY   OF   CILIA  IN   ACTION 27 

LESSON    IX. 

THE   CONNECTIVE   TISSUES  :   AREOLAR   AND   ADIPOSE   TISSUE  ...        29 


LESSON   X. 

THE   CONNECTIVE    TISSUES    (continued)  '.    ELASTIC  TISSUE.    FIBROUS   TISSUE, 

SPECIAL   VARIETIES — DEVELOPMENT    OF   CONNECTIVE    TISSUE    .  .      .        35 


LESSON   XL 

THE   CONNECTIVE   TISSUES    (continued)  :   ARTICULAR   CARTILAGE  .  .        41 

LESSON   XII. 

THE    CONNECTIVE    TISSUES     (continued)  \     COSTAL    CARTILAGE,    FIBRO-CAR- 

TILAGE 45 

LESSON     XIII. 
THE    CONNECTIVE    TISSUES    (COnti)Utcd)  \    BONE    AND   MARROW        ...        48 

LESSON    XIV. 

THE    CONNECTIVE    TISSUES    (continued)  :    DEVELOPMENT    OF   BONE  .  .      .        54 

LESSONS   XV.   and   XVI. 

STRUCTURE   OF   MUSCLE ■    .  .61 

LESSON   XVII. 

STRUCTURE   OF   NERVE-FIBRES 69 

LESSON   XVIII. 

STRUCTURE   OF   NERVE-CELLS 75 

LESSON   XIX. 

MODES    OF   TERMINATION   OF   NERVE-FIBRES     .  .  .      .         80 

LESSON    XX. 

STRUCTURE  OF  THE  LARGER  BLOOD-VESSELS 87 


CONTEXTS  vii 

LESSON   XXI. 

PAGE 
SMALLER     BLOOD-VESSELS,      LYMPHATIC      VESSELS,      SEROUS      MEMBRANES, 

SYNOVIAL   MEMBRANES 92 

LESSON   XXII. 

LYMPHATIC   GLANDS,   TONSIL,    THYMUS i00 

LESSON   XXIII. 

THE    SKIN 105 

LESSON    XXIV. 

STRUCTURE   OF   THE   HEART 115 

LESSON   XXV. 

THE    TRACHEA   AND   LUNGS 119 

LESSON    XXVI. 

STRUCTURE    OF   THE    TEETH.    THE    TONGUE.    AND    MUCOUS    MEMBRANE    OF 

THE    MOUTH 125 

LESSON   XXVII. 

THE   SALIVARY   GLANDS 136 

LESSON   XXVIII. 

THE  STRUCTURE  OF  THE  STOMACH HI 

LESSONS   XXIX.   and   XXX. 

STRUCTURE   OF   SMALL   AND   LARGE    INTESTINE 146 

LESSON   XXXI. 

STRUCTURE    OF   THE   LIVER   AND    PANCREAS 154 

LESSON   XXXII. 

STRUCTURE  OF  THE  SPLEEN,  SUPRARENAL  CAPSULE,  AND  THYROID  BODY  .   159 

LESSON    XXXIII. 

STRUCTURE    OF   THE    KIDNEY 164 


viii  CONTEXTS 

LESSON   XXXIV. 

PAGE 
STRUCTURE   OF   THE   URETER,   BLADDER,   AND   MALE   GENERATIVE   ORGANS    .      171 

LESSON   XXXV. 

GENERATIVE    ORGANS    OF   THE   FEMALE.    AND    MAMMARY    GLANDS  .  .  .178 

LESSON   XXXVI. 

STRUCTURE   OF   THE   SPINAL   CORD 185 

LESSON   XXXVII. 

THE   MEDULLA   OBLONGATA,  PONS  VAROLII,   AND   MESENCEPHALON  .  .192 

LESSON   XXXVIII. 

STRUCTURE    OF   THE    CEREBELLUM   AND    CEREBRUM 201 

LESSONS   XXXIX.   and   XL. 

STRUCTURE   OF   THE   EYELIDS   AND   OF   THE    PARTS   OF   THE   EYEBALL  .  .211 

LESSON   XLL 

STRUCTURE    OF   THE   OLFACTORY,  MUCOUS  MEMBRANE  AND  OF  THE  EXTERNAL 

AND   MIDDLE    EAR 228 

LESSON   XLII. 

STRUCTURE   OF   THE   LABYRINTH 232 


APPENDIX ,  24i 


THE    ESSEX 


HISTOLOGY. 


INTRODUCTORY. 

ENUMERATION  OF   THE    TISSUES   AND   THE    GENERAL 
STRUCTURE   OF  ANIMAL   CELLS. 

Animal  Histology1  is  the  science  which  treats  of  the  minute  struc- 
ture of  the  tissues  and  organs  of  the  animal  body  ;  it  is  studied  with 
the  aid  of  the  microscope,  and  is  therefore  also  termed  Microscopical 
Anatomy. 

Every  part  or  organ  of  the  body,  when  separated  into  minute  frag- 
ments, or  when  examined  in  thin  slices  (sections),  is  found  to  consist  of 
certain  textures  or  tissues,  which  differ  in  their  arrangement  in  different 
organs,  but  each  of  which  exhibits  characteristic  structural  features. 

The  following  is  a  list  of  the  principal  tissues  which  compose  the 
body  :  — 


1.  Epithelial. 


2.  Connective  - 


8.  Muscular 


1.   Nervous. 


f  Areolar 

Fibrous 

Elastic 

Adipose 
|  Lymphoid 

Cartilage 
I  Bone 
|  Voluntary 
-  Involuntary  or  plain 
I  Cardiac 


Some  organs  are  formed  of  several  of  the  above  tissues,  others 
contain  only  one  or  two. 

It  is  convenient  to  include  such  fluids  as  the  blood  and  lymph 
amongst  the  tissues,  because  they  arc  studied  in  the  same  manner  and 
contain  cellular  elements  similar  to  those  met  with  in  some  of  the 
other  tissues. 

The  elements  which  compose  the  tissues  are  of  the  nature  either 

1  From  iVtos,  a  web  or  texture. 


•2  THE   ESSENTIALS  OF  HISTOLOGY 

of  fibres  or  cells.  Some  tissues  are  composed  almost  entirely  of  fibres 
with  relatively  few  cells  interspersed  amongst  the  fibres  ;  this  is  the 
case  with  most  of  the  connective  tissues.  Others  are  composed  entirely 
of  cells,  which,  however,  may  in  some  cases  be  prolonged  so  as  to  form 
fibres ;  but  these  are  different  from  the  fibres  of  the  connective  tissues 
in  being  formed  directly  from  the  cells  of  the  tissue,  whereas  the  fibres 
of  the  connective  tissues  are  formed  between  the  cells  in  an  intercellular 
substance.  Tissues  which  are  entirely  composed  of  cells  are  the  epithe- 
lial tissues,  whilst  nervous  and  muscular  tissue  are  formed  of  cells 
which  are  partly  or  wholly  extended  so  as  to  form  fibres. 

Cells. — In  the  early  embryo  the  whole  body  is  an  agglomeration 
of  cells.  These  are  minute  portions  of  living  substance  or  protoplasm, 
enclosing  a  vesicle  which  is  known  as  the  nucleus.  The  tissues  are 
subsequently  formed  either  by  changes  which  occur  in  the  intercellular 
substance,  or  by  changes  in  the  cells  themselves ;  frequently  by  both 
these  processes  combined.  The  cells  which  are  least  altered  from 
their  embryonic  condition  are  the  white  corpuscles  of  the  blood,  and 
these  may  be  regarded  therefore  as  typical  cells. 

The  protoplasm  of  a  cell  (fig.  l,p)  is  composed  of  a  soft  albuminous 
substance,  which  is  characterised  in  typical  cells  by  possessing  the 
property  of  spontaneous  movement.  When  the  cell  is  unenclosed  by  a 
membrane  a  change  in  the  shape,  or  even  in  the  position  of  the  cell, 
may  be  thereby  produced  (amoeboid  movement).  The  protoplasm 
often  contains  granules  of  various  kinds  or  droplets  of  watery  fluid 
(vacuoles) ;  the  latter  may  be  present  in  sufficient  abundance  to  impart 
a  reticular  or  sponge-like  structure  to  the  protoplasm.  In  some  cells 
the  protoplasm  has  a  striated  or  fibrillar  structure. 

The  nucleus  of  the  cell  (fig.  1,  n)  is  a  minute  vesicle  embedded  in 

the  protoplasm.     It  is  bounded  by  a  membrane  which  encloses  a  clear 

substance  {nuclear  matrix),  and  the  whole  of 

this  substance  is  generally  pervaded  by  an 

irregular  network   Of  fibres,    some  coarser, 

others  finer  (intranuclear  neticork,  n').   This 

intranuclear  network  often  exhibits  one  or 

more   enlargements,   which   are   known   as 

the  nucleoli.    The  fibres  within  the  nucleus 

have  been  observed  to  undergo  spontaneous 

changes  of  form  and  arrangement,  but  this 

l.— Diagram  of  a  cell,  becomes  much  more  evident  when  the  cell 

^SE:,S"S  is  about  to  divide.    The  division  of  the  proto- 

nuciear  network, «',  and  nucieo-  piasm  is  always  preceded  by   that  of  the 

nucleus,  and  the  intranuclear  fibres  undergo 

during  its  division  a  series  of  remarkable  changes   in   arrangement 

and  position,  which  are  known  collectively  by  the  term  karyomitosis 

(karyokinesis).     These  changes  may  best  be  studied  in  the  division 

of  epithelium-cells  (see  Lesson  VI.),  but  exactly  similar  phenomena 

have  been  shown  to  occur  in  cells  belonging  to  the  other  tissues.     In 


INTRODUCTION 


3 


Ectoderm 

or 
Epiblast 


some  cases  it  may  be  observed  that  the  filaments  of  the  intranuclear 
network  are  made  up  of  fine  juxtaposed  particles,  arranged  either  in  a 
single  or  a  double  row. 

All  the  embryonic  cells  are  formed  from  the  division  of  the  ovum 
or  egg-cell,  which  divides  first  into  two  cells,  these  again  into  two,  and 
so  on  until  a  large  number  of  cells  (embryonic  cells)  are  produced. 
Eventually  these  resultant  cells  arrange  themselves  in  the  form  of  a 
membrane  (blastoderm)  which  is  composed  of  three  layers.  These 
layers  are  known  respectively  as  the  ectoderm  or  epiblast,  the  meso- 
derm or  mesoblast,  and  the  entoderm  or  hypoblast.  The  ectoderm 
gives  rise  to  most  of  the  epithelial  tissues  and  the  tissues  of  the  nervous 
system ;  the  entoderm  to  the  epithelium  of  the  alimentary  canal 
(except  the  mouth),  and  the  glands  in  connection  with  it;  and  the 
mesoderm  to  the  connective  and  muscular  tissues. 

The  histogenetical  relation  between  the  three  layers  of  the  blasto- 
derm and  the  several  tissues  and  organs  of  the  body  is  exhibited  in  the 
following  table  : — 

-The  epithelium  of  the  skin  or  epidermis,  and  its  appendages 
viz.,  the  hairs,  nails,  sebaceous  and  sweat  glands. 

The  epithelium  of  the  mouth,  and  of  the  salivary  and  other 
glands  which  open  into  the  mouth.  The  enamel  of  the 
teeth.     The  gustatory  organs. 

The  epithelium  of  the  nasal  passages,  and  the  cavities  and  glands 
which  open  into  them. 

The  epithelium  covering  the  front  of  the  eye.  The  crystalline 
lens.     The  retina. 

The  epithelium  lining  the  membranous  labyrinth  of  the  ear. 

The  epithelium  lining  the  central  canal  of  the  spinal  cord  and 
the  fourth,  third,  and  lateral  ventricles  of  the  brain. 

The  tissues  of  the  nervous  system. 
t-The  pituitary  body.     The  pineal  gland. 
("The  connective  tissues. 

The  blood  and  lymph  corpuscles. 

The  epithelial  lining  of  the  heart,  blood-vessels,  lymphatics,  and 
serous  membranes. 

The  epithelium  of  the  uriniferous  tubules  (in  part). 

The  epithelium  of  the  generative  organs,  and  the  generative  pro- 
ducts in  both  sexes. 

The  muscular  tissues,  voluntary,  involuntary  and  cardiac  (except 
the  muscular  fibres  of  the  sweat  glands,  which  are  epiblastic 
m  origin). 
-The  spleen  and  other  lymphatic  and  vascular  glands. 
'The  epithelium  of  the  alimentary  canal  (from  the  pharynx  to 
the  lower  end  of  the  rectum)  and  all  the  glands  which  open 
into  it  (including  the  liver  and  pancreas). 

The  epithelium  of  the  Eustachian  tube  and  cavity  of  the  tym- 
panum. 
■j  The  epithelium  of  the  larynx,  trachea,  and  bronchi,  and  of  all 
their    ramifications.      The   epithelium   of   the   puhnonary 
alveoli. 

The  epithelium  of  the  thyroid  body.    Part  of  the  thymus  gland. 

The  epithelium  of  the  urinary  bladder  and  ureters,  and  of  part 
of  the  uriniferous  tubules. 

b2 


Mesoderm 

or 
Mesoblast 


Entoderm 

or 
Hypoblast 


THE   ESSENTIALS   OF   HISTOLOGY 


LESSON   I. 

USE   OF  THE   MICROSCOPE.     EXAMINATION  OF 
COMMON   OBJECTS. 

The  requisites  for  practical  Histology 
are  a  good  compound  microscope  mag- 
nifying from  about  50  to  400  linear  ;  slips- 
of  glass  technically  known  as  '  slides,' 
upon  which  the  preparations  are  made ; 
small  pieces  of  thin  glass  used  as  covers 
for  the  preparations  ;  a  few  simple  instru- 
ments, such  as  a  razor,  a  scalpel,  scissors, 
fine-pointed  forceps,  and  needles  mounted 
in  wooden  handles ;  and  a  set  of  fluid  re- 
agents for  mounting  and  staining  micro- 
scopic preparations.1  A  sketch-book  and 
pencil  are  also  requisite,  and  must  be  con- 
stantly employed. 

Examine  the  microscope  (fig.  2).  It 
consists  of  a  tube  (t  t')  having  two  systems 
of  lenses,  one  at  the  upper  end  termed 
the  '  eye-piece  '  or  '  ocular  '  (oc),  the  other, 
at  the  lower  end,  termed  the  '  objective  ' 
(obj).  There  should  be  at  'least  two 
objectives — a  low  power,  working  at  about 
i  inch  from  the  object,  and  a  high  power, 
having  a  focal  distance  of  about  £  inch. 
The  focus  is  obtained  by  cautiously  bring- 
ing the  tube  and  lenses  down  towards  the 
object  by  the  coarse  adjustment,  which  is 
either  a  telescopic  or  a  rack-and-pinion 
movement  (adj),  and  focussing  exactly  by 
the  fine  adjustment,  which  is  always  a 
finely  cut  screw  (adj'). 

The  stage  (st)  upon  which  the  prepa- 
rations are  placed  for  examination,  the 
mirror  (m)  which  serves  to  reflect  the  lit,rht 
up  through  the  central  aperture  in  the 
stage  and  along  the  tube  of  the  instrument, 
and  the  diaphragm  (d)  below  the  stage 
which  serves  to  regidate  the  amount  of 
light  thus  thrown  up,  are  all  parts  the 
employment  of  which  is  readily  under- 
stood. 

It  is  convenient  to  begin  the  study  of 
2.— Diagram  of  Microscope,    histology  by  the  examination  of  the  blood, 

'  The  directions  for  making  the  principal  fluids  used  in  histological  work  will 
be  found  in  the  Appendix. 


Fig. 


USE   OF   THE   MICROSCOPE 


5 


but  before  doing  this  the  student  should  endeavour  to  familiarise  himself 
with  the  use  of  the  microscope,  and  at  the  same  time  learn  to  recognise  some 
of  the  chief  objects  which  are  liable  to  occur  accidentally  in  microscopic 
specimens.     On  this  account  it  has  been  considered  desirable  to  introduce 


Fig.  3. — Organic  matters  frequently  present  in  dvst.     (Heitzmann.) 

S,  fibres  of  silk  ;  C,  of  cotton  ;  L,  of  linen  :  H'.  of  wool  ;  F,  feather  ;  St,  starch-granules  :  f>, 
cork;  0,  spores  oi  mildew;  M,  mycelium  or  threads  oi  mildew;  Mc,  micrococci;  B,  bac- 
teria; Li,  leptothrix  filameuts  (50U  diameters). 


directions  for  the  examination  of  starch-granules,  air-bubbles,  linen,  cotton, 
and  woollen  fibres,  and  the  usual  constituents  of  the  dust  of  a  room,  into  the 
first  practical  lesson. 


6  THE  ESSENTIALS  OF  HISTOLOGY 

1.  Examination  of  starch-granules.  Gently  scrape  the  cut  surface  of  a 
potato  with  the  point  of  a  knife  :  shake  the  starch-granules  so  obtained  into 
a  drop  of  water  upon  a  clean  slide  and  apply  a  cover-glass. 

With  the  low  power  the  starch-granules  look  like  dark  specks  differing 
considerably  in  size  ;  under  the  high  power  they  are  clear,  flat,  ovoid  particles 
(fig.  3,  St),  with  a  sharp  outline  when  exactly  focussed.  Notice  the  change  in 
appearance  of  the  outline  as  the  microscope  is  focussed  up  or  down.  On  close 
examination  fine  concentric  lines  are  to  be  seen  in  the  granules  arranged 
around  a  minute  spot  which  is  generally  placed  eccentrically  near  the  smaller 
end  of  the  granule.     Sketch  two  or  three  starch-granules. 

Notice  the  appearance  of  air-bubbles  in  the  water.  If  comparatively 
large  they  are  clear  in  the  middle,  with  a  broad  dark  border  due  to  refraction 
of  the  light ;  if  small  they  may  look  entirely  dark. 

2.  Examine  fibres  of  linen  and  of  cotton  in  water,  using  a  high  power. 
Compare  the  well-defined,  relatively  coarse,  striated,  and  slightly  twisted  linen- 
with  the  longer,  finer,  and  more  twisted  cotton-fibres.  Sketch  one  of  each 
kind. 

3.  Mount  two  or  three  hairs  from  the  head  in  water  and  look  at  them, 
first  with  the  low,  then  with  the  high  power.  Examine  also  some  fibres 
from  any  woollen  material  and  compare  them  with  the  hairs.  They  have 
the  same  structure,  although  the  wool  is  finer  and  is  curled ;  its  structure 
may  be  partly  obscured  by  the  dye.     Draw  one  or  two  woollen  fibres. 

4.  Examine  some  dust  of  the  room  in  water  with  a  high  power.  In 
addition  to  numerous  groups  of  black  particles  of  carbon  (soot)  there  will 
probably  be  seen  fibres  of  linen,  cotton,  or  wool,  and  shed  epitheliurn-cells 
derived  from  the  epidermis. 

5.  Prepare  a  scale  to  serve  for  measuring  objects  under  the  microscope.  To 
do  this  put  a  stage-micrometer  (which  is  a  glass  slide  ruled  in  the  centre,  with 
the  lines  ^  and  —  millimeter  apart)  under  the  microscope  in  such  a  manner 
that  the  lines  run  frorn  left  to  right  (the  microscope  must  not  be  inclined). 
Focus  them  exactly.  Put  a  piece  of  white  card  on  the  table  at  the  right  of 
the  microscope.  Look  through  the  instrument  with  the  left  eye,  keeping  the 
right  eye  open.  The  lines  of  the  micrometer  will  appear  projected  upon  the 
paper.  Mark  their  apparent  distance  with  pencil  upon  the  card,  and  after- 
wards make  a  scale  of  lines  in  ink  the  same  interval  apart.  A  magnified  repre- 
sentation is  thus  obtained  of  the  micrometer  scale.  Mark  upon  it  the  number 
of  the  eye-piece  and  of  the  objective,  and  the  length  of  the  microscope  tube. 
This  scale-card  will  serve  for  the  measurement  of  any  object  without  the 
further  use  of  the  micrometer.  To  measure  an  object,  place  the  scale-card 
upon  the  table  to  the  right  of  the  microscope  and  view  the  object  with  the 
left  eye,  keeping  the  right  eye  open.  The  object  appears  projected  upon 
the  scale,  and  its  size  in  ~  or  ~  of  a  millimeter  can  be  read  off.  It  is 
important  that  the  same  objective  and  eye-piece  should  be  employed  as  were 
used  in  making  the  scale,  and  that  the  microscope  tube  should  be  of  the  same 
length. 


LESSON   II. 

STUDY  OF  THE  HUMAN  BLOOD -CORPUSCLES. 

1.  Having  cleaned  a  slide  and  cover-glass,  prick  the  finger  and  mount  a 
small  drop  of  blood  quickly,  so  that  it  has  time  neither  to  dry  nor  to  coagulate. 
Examine  it  at  once  with  the  high  power. 

Note  (a)  the  coloured  corpuscles,  mostlj-  in  rouleaux  and  clumps,  but  some 
lying  apart  seen  flat  or  in  profile  ;  (6)  the  colourless  corpuscles,  easily  made 
out  if  the  cover-glass  is  touched  by  a  needle,  on  account  of  their  tendency  to 
stick  to  the  glass,  whilst  the  coloured  corpuscles  are  driven  past  by  the  cur- 
rents set  up  ;  (c)  in  the  clear  spaces,  fibrin  filaments  and  elementary  particles 
or  blood-tablets. 

Sketch  a  roll  of  coloured  corpuscles  and  one  or  two  colourless  corpuscles. 
Count  the  number  of  colourless  corpuscles  in  a  field  of  the  microscope. 

2.  To  be  made  like  1,  but  the  drop  of  blood  is  to  be  mixed  upon  the  slide 
with  an  equal  amount  of  0"6  per  cent,  salt  solution,  so  that  the  red  corpuscles 
tend  to  be  less  massed  together,  and  their  peculiar  shape  is  better  displayed. 

Sketch  a  red  corpuscle  seen  on  the  flat  and  another  in  profile  (or 
optical  section).     Also  a  crenated  corpuscle. 

Measure  ten  red  corpuscles,  and  from  the  results  ascertain  the  average 
diameter  of  a  corpuscle. 

3.  Make  a  preparation  of  blood  as  in  §  1  and  put  it  on  one  side  to  coagu- 
late. After  fifteen  minutes  allow  a  drop  of  a  solution  of  borax-carmine '  to 
run  under  the  cover-glass.  This  decolorises  the  red  corpuscles,  but  stains 
the  nuclei  of  the  white  corpuscles  and  brings  the  network  of  fibrin  filaments 
and  the  elementary  particles  clearly  into  view  (fig.  7).  After  a  drop  of  gly- 
cerine has  been  allowed  to  diffuse  into  the  fluid  the  cover-glass  may  be 
cemented  with  gold-size  and  the  preparation  labelled  and  kept. 

4.  Enumeration  of  the  blood-corpuscles.  This  is  readily  effected  by  the 
hemacytometer  of  Gowers.  This  instrument  consists  of  a  glass  slide  (tig.  4,  c), 
the  centre  of  which  is  ruled  into  -^  millimeter  squares  and  surrounded  by  a 
glass  ring  \  mm.  thick.  It  is  provided  with  measuring  pipettes  (a  and  b),  a 
vessel  (d)  for  mixing  the  blood  with  a  saline  solution  (sulphate  of  soda  of  sp. 
gr.  1015),  glass  stirrer  (e)  and  guarded  needle  (f). 

'  The  mode  of  proceeding  is  extremely  simple.  995  cubic  millimeters  of 
the  saline  solution  are  placed  in  the  mixing  jar;  5  cubic  millimeters  of  blood 
are  then  drawn  from  a  puncture  in  the  finger  and  blown  into  the  solution. 
The  two  fluids  are  well  mixed  by  the  Btirrer  and  a  small  drop  of  this  dilution  is 
placed  in  the  centre  of  the  cell,  the  cover-glass  gently  laid  on  (so  as  to  touch 
the  drop,  which  thus  forms  a  layer  \  nun.  thick  between  the  slide  and  cover- 
glass)  and  pressed  down  by  two  brass  springs.  In  a  lew  minutes  the  cor- 
puscles have  sunk  to  the  bottom  of  the  layer  of  fluid  and  rest  on  the  squares. 
The  Dumber  in  ten  Bqnares  is  then  counted,  and  this,  multiplied  by  10,000, 
gives  the  number  in  a  cubic  millimeter  of  blood.' 

1  See  Appendix. 


THE   ESSENTIALS  OF  HISTOLOGY 


Fig.  4. — Hemacytometer  of  Gowers. 


o 


Fig.  5. — Human  blood  as  seen  on  the  warm 
stale.     (Magnified  about  1,200  diameters.) 

r,  r,  single  red  corpuscles  seen  lying  flat  ;  /'.  /•',  red  cor- 
puscles on  their  edge  and  viewed  in  profile  ;  >■".  red 
corpuscles  arranged  in  rouleaux  ;  c,  c,  crenate  red  cor- 
puscles; p,  a  finely  granular  pale  corpuscle;  g,  a 
coarsely  granular  pale  corpuscle.  Both  have  two  or 
three  distinct  vacuoles,  and  were  undergoing  changes 
of  shape- at  the  moment  of  observation  ;  in  <j.  a  nucleus 
also  is  visible. 


Fig.  6. — Human  red  corpus- 
cles  lying  singly  and  col- 
lei  ted  into  rolls.  (As  seen 
under  an  ordinary  high  power 
of  the  microscope.) 


STUDY  OF   THE   HUMAN   BLOOD-CORPUSCLES  9 

The  coloured  blood-corpuscles. — Under  the  microscope  the  blood  is 
seen  to  consist  of  a  clear  fluid  (plasma  I,  in  which  are  suspended  the  blood- 
corpuscles  (tig.  5).  The  latter  are  of  two  kinds:  the  red  ox  coloured 
(r,  r '),  which  are  by  far  the  most  numerous,  and  the  white,  pale,  or 
colourless  (p,  g),  which  from  their  occurrence  in  the  lymph  are  also 
known  as  lymph-corpuscles.  When  seen  singly  the  coloured  corpuscles 
are  not  distinctly  red,  but  appear  of  a  reddish-yellow  tinge.  In  the 
blood  of  man  and  of  all  other  mammals,  except  the  Camelida?,  they 
are  biconcave  circular  disks.  Their  central  part  usually  has  a  slightly 
shaded  aspect,  under  the  ordinary  high  power  (fig.  6,  1),  but  this  is  due 
to  their  biconcave  shape,  not  to  the  presence  of  a  nucleus.  They  have 
a  strong  tendency  to  become  aggregated  into  rouleaux  and  clumps  when 
the  blood  is  at  rest,  but  if  it  is  disturbed  they  readily  become  separated. 

If  the  density  of  the  plasma  is  increased  in  any  way,  as  by  evapo- 
ration, many  of  the  red  corpuscles  become  shrunken  or  crenated  (c). 

The  average  diameter  of  the  human  red  corpuscles  is  0'077  milli- 
meter (about  3oVo  inch).1 

There  are  from  four  to  five  millions  of  coloured  corpuscles  in  a  cubic 
millimeter  of  blood. 

The  colourless  corpuscles  of  human  blood  are  a  little  larger  than 
the  coloured,  measuring  O01  mm.  ( a  -^  0-  inch  >  in  diameter.  They 
are  far  fewer,  numbering  not  more  than  ten  thousand  in  a  cubic 
millimeter.  Moreover  they  are 
specifically  lighter,  and  tend  to 
come  to  the  surface  of  the  prepara- 
tion. If  examined  soon  after  the 
blood  is  drawn,  they  are  usually 
spheroidal  in  shape,  but  they  soon 
become  irregular  (fig.  5,  p,  g),  and 
their  outline  continually  alters, 
owing  to  the  amoeba-like  changes 
of  form  to  which  they  are  subject. 
Some  of  the  colourless  corpuscles 
are  very  pale  and  finely  granular,    FlG-  ?•— Fibris-filaments  and  blood- 

•     L  J     &  TABLETS. 

others   contain   coarser   and   more  ,   na*„„v  ~*  «v™„  -i  ™„  ,«„      i  • 

A.  network  of  fibrin,  shown  after  waslnnp  away 

distinct     granules     in      their    protO-      the  corpuscles  from  a  preparation  of  bl Ittaat 

,  .  L  has  been  allowed  to  clot ;  many  of  the  fil 

plasm.       lhe   protoplasm    may  also     radiate   from   small  clumps  of  bl 1-1 

i.    •  ,    _i_____  i  B  (from  Osier),  blood-corpuscles  and  elei 

Contain    Clear    spaces    or    vacuoles,     tary  particles  or  blood-tablets,  within  a  small 

and  a  reticular  structure  is  described    vem> 

in  it   by  some  histologists.     Each  pale  corpuscle  has   one   or   more 

nuclei,  which  are  difficult  to  see  without  the  aid  of  reagents. 

In  the  clear  fluid  in  which  the  corpuscles  are  suspended,  a  network 
of  fine  straight  intercrossing  filaments  (fibrin)  soon  makes  its  ap- 
pearance (fig.  7).      There  are  also  to  be  seen  a  certain   number   of 

1  The  following  list  gives  the  diameter  in  parts  of  a  millimeter  of  the  red  blood- 
oorpusclea  of  some  of  the  common  domestic  animals  : — Dog,  OOUTo  ;  rabbit,  U0009 ; 
cat,  0-0005  ;  sheep,  0-UOoU  ;  goat,  00U41. 


10 


THE   ESSENTIALS  OF  HISTOLOGY 


minute  round  colourless  discoid  particles,  either  separate  or  collected 
into  groups  or  masses,  which  may  be  of  considerable  size.  These  are 
the  elementary  particles  or  blood-tablets.  Their  meaning  is  not  known. 
Fatty  particles  may  also  occur  in  the  plasma. 

Development  of  blood-corpuscles. — In  the  embryo,  the  first-formed 
coloured  blood-corpuscles  are  amoeboid  nucleated  cells,  the  protoplasm 


Fig.  8. — Development  of  blood-vessels  and  blood-corpuscles  in  the  vascolar 
area  of  the  guinea-pig. 

hi,  blood-corpuscles  becoming  free  in  the  interior  of  a  nucleated  protoplasmic  mass. 

of  which  contains  haemoglobin.  These  embryonic  blood-corpuscles 
are  developed  within  cells  of  the  mesoderm,  which  unite  with  one 
another  so  as  to  form  a  protoplasmic  network  (fig.  8).  The  nuclei 
then  multiply,  and  around  some  of  them  there  occurs  an  aggregation 
of  coloured  protoplasm.     Next  the  branched  cells  become  hollowed 


Fig.  9. — Blood-corpuscles  developing  within  connective-tissue  cells. 

h,  a  cell  containing  diffused  haemoglobin  ;  h',  globular  masses  of  coloured  substance  in  the 
protoplasm,  within  which  also  are  numerous  vacuoles  ;  h",  a  cell  filled  with  coloured 
globules. 

out  by  an  accumulation  of  fluid  in  their  protoplasm  so  as  to  form  a 
network  of  blood-vessels,  and  then  the  coloured  nucleated  portions 
of  protoplasm  are  set  free  within  them  as  the  embryonic  blood- 
corpuscles  (fig.  8,  bl). 


DEVELOPMENT   OF   THE  BLOOD-CORPUSCLES 


11 


In  later  embryonic  life,  and  after  birth,  nucleated  coloured  cor- 
puscles are  no  longer  present  in  mammalian  blood,  but  are  replaced 
by  the  usual  discoid  corpuscles.  These  are  formed  within  certain  cells 
of  the  connective  tissue,  a  portion  of  the  protoplasm  of  the  cell  becom- 
ing coloured  by  haemoglobin,  and  separated  into  globular  particles 
(fig.  9,  h,  h',  h"),  which  are  gradually  moulded  into  disk-shaped  red 
corpuscles.  In  the  meantime  the  cells  become  hollowed  out,  and  join 
with  similar  neighbouring  cells  to  form  blood-vessels  (fig.  10,  a,  b,  c). 
The  process  is  therefore  the  same  as  before,  except  that  the  cell-nuclei 
do  not  participate  in  it. 


Fig.  10. — Further  development  of  blood-corpuscles  in  connective-tissue  cells, 
and  transformation  of  the  latter  into  capillary  blood-vessels. 

a,  an  elongated  cell  with  a  cavity  in  its  protoplasm  occupied  by  fluid  and  by  blood-corpus- 
cles mostly  globular;  b,  a  hollow  cell  the  nucleus  of  which  has  multiplied.  The  new 
nuclei  are  arranged  around  the  wall  of  the  cavity,  the  corpuscles  in  which  have  now 
become  discoid;  c  shows  the  mode  of  union  of  a  ' haemapoietic '  cell,  which  in  this  in- 
stance contains  only  one  corpuscle,  with  the  prolongation  (6/)  of  a  previously  existing 
vessel,    a,  and  c,  from  the  new-born  rat ;  6,  from  a  foetal  sheep. 

Although  no  nucleated  coloured  corpuscles  are  to  be  seen  in  the 
blood  in  post-embryonic  life,  they  continue  to  be  found  in  the  marrow 
of  the  bones  (see  Lesson  XIII.),  and  it  is  thought  probable  that  the 
red  disks  may  be  formed  in  some  way  from  these.  Others  have  sup- 
posed that  the  red  disks  are  derived  from  the  white  corpuscles  of  the 
blood  and  lymph,  and  others  again  that  they  are  developed  from  the 
blood-tablets  ;  but  the  evidence  in  favour  of  these  views  is  insufficient. 

The  white  blood -corpuscles  and  hpnph-corpuscles  occur  originally 
as  free  unaltered  embryonic  cells,  which  have  found  their  way  into  the 
vessels  from  the  circumjacent  tissues.  Later  they  become  formed  in 
lymphatic  glands  and  other  organs  composed  of  lymphoid  tissue,  and 
pass  from  these  directly  into  the  lymphatics  and  so  into  the  blood. 


12  THE   ESSENTIALS   OF  HISTOLOGY 


LESSON   III. 

ACTION   OF  REAGENTS    UPON  THE    HUMAN  BLOOD- 
CORPUSCLES. 

1.  Make  a  preparation  of  blood  as  in  Lesson  II.   1,  and  apply  a  drop  of 
water  at  one  edge  of  the  cover-glass.     Examine  at  a  place  where  the  two 
fluids  are  becoming  mixed.     Notice  particularly  the  first  effect  of  water  upon 
both  red  and  white  corpuscles,  as  well  as  the  ultimate  action. 
Sketch  both  kinds  of  corpuscles  under  the  action  of  water. 

2.  Eepeat  on  another  preparation,  using  very  dilute  alkali  (0*2  per  cent, 
potash  in  salt  solution)  instead  of  water.  Notice  the  complete  solution  first 
of  the  white  and  then  of  the  coloured  corpuscles  as  the  alkali  reaches  them. 

3.  Eepeat  on  another  preparation,  using  dilute  acetic  acid  (1  per  cent.). 
Observe  that  the  effect  of  the  acid  upon  the  coloured  corpuscles  is  similar  to 
that  of  water,  but  that  it  has  a  different  action  upon  the  colourless  corpuscles. 

Sketch  two  or  three  of  the  latter  after  the  action  is  completed. 

4.  Make  a  preparation  of  blood  mixed  with  salt  solution  as  in  Lesson  II.  2, 
and  investigate  the  action  of  tannic  acid  (2  per  cent,  solution)  hi  the  same 
way. 

Sketch  two  or  three  coloured  corpuscles  after  the  action  is  complete. 


The  action  of  reagents  upon  the  human  red  blood-corpuscles  shows 
that,  although  to  all  appearance  homogeneous,  they  in  reality  consist 

of  an  intimate  intermixture  of  the  colour - 

a,       h         e         d       e         ing  matter  or  haemoglobin  with  certain 

^      £}      ^    ^       other  substances  (globulin,  lecithin,  chfe- 

■  lesterin),  which  are  left  as  the  colourless 

lv  stroma,    on    dissolving   out   the    ha?ino- 

^•%^t  y  kJI      globin,  or   on  causing  its  discharge   by 

any  means   from   the    corpuscle.      This 
11#  separation  of  the  haemoglobin  from  the 

a-e,  successive  effects  of  water  upon  a  l^fxji  /.cii 

red  corpuscle ;/,  effect  of  solution  of  stroma  can  be  effected  by  water  (fig.  11, 

salt;  y,  effect  of  tannic  acid.  a_e)    an(J    also    ty.    d&ute    acids,    by    the 

action  of  heat  (60°  C.)»  the  freezing  and  thawing  of  blood,  the  vapour 
of  chloroform,   and  the  passage   of  electric   shocks  through   blood.1 

'  In  the  blood  of  some  animals  crystals  of  haemoglobin  readily  form  after 
its  separation  by  any  of  these  means  from  the  red  corpuscles.  These  crys- 
tals are  rhombic  prisms  in  most  animals,  but  tetrahedra  in  the  guinea-pig,  and 
hexagonal  plates  in  the  squirrel.  They  are  most  appropriately  studied  along 
with  the  chemical  and  physical  properties  of  blood,  and  are  therefore  omitted 
here.  The  same  remark  applies  to  the  minute  dark-brown  rhombic  crystals 
(hczmiri),  which  are  formed  when  dried  blood  is  heated  with  glacial  acetic  acid, 
and  to  the  reddish-yellow  crystals  of  licematoidin,  which  are  found  in  old  blood 
extravasations. 


ACTION  OF  REAGENTS   UPON   HUMAN   BLOOD  13 

The  mixing  of  human  blood  with  the  blood  or  serum  of  various  animals 
also  has  a  similar  action,  probably  owing  to  differences  of  density  or 
alkalinity.  Tannic  acid  produces  a  peculiar  effect  (fig.  11,  g) ;  the 
haemoglobin  is  discharged  from  the  stroma,  but  is  immediately  altered 
and  precipitated,  remaining  adherent  to  the  stroma  in  the  form  of  a 
round  or  irregular  globule  of  a  brownish  tinge  (haematin). 

The  structure  of  the  colourless  corpuscles  is  also  brought  out  by 
the  action  of  these  reagents.  As  the  water  reaches  them  their  amoe- 
boid movements  cease  ;  they  become  swollen  out  into  a  globular  form 
by  imbibition  of  fluid  (fig.  12,  i),  and  the  granules  within  the  proto- 


Fig.  12. 

1,  first  effect  of  the  action  of  water  upon  a  white  blood-corpuscle  ;  2,  3,  white  corpuscles 
treated  with  dilute  acetic  acid  ;  n,  nucleus. 

plasm  can  be  seen  to  be  in  active  Brownian  motion.  Their  nuclei 
also  become  clear  and  globular,  and  are  more  conspicuous  than  before. 
With  the  further  action  of  the  water,  the  corpuscle  bursts  and  the 
granules  are  set  free. 

Acids  have  an  entirely  different  action  upon  the  white  corpuscles. 
Their  nuclei  become  somewhat  shrunken  and  very  distinct  ifig.  12, 
•2  and  3i,  and  a  granular  precipitate  is  formed  in  the  protoplasm  around 
the  nucleus.  At  the  same  time,  a  part  of  the  protoplasm  generally 
swells  out  so  as  to  form  a  clear  bleb-like  expansion  (an  appearance 
which  often  accompanies  the  death  of  the  corpuscle  from  other 
causes). 


14  THE   ESSENTIALS   OF  HISTOLOGY 


LESSON   IV. 

STUDY  OF  THE  BLOOD-CORPUSCLES   OF  AMPHIBIA. 

1.  Mount  a  drop  of  newt's  blood  obtained  from  tbe  cut  end  of  the  tail. 
Examine  with  the  high  power.  Notice  the  shape  of  the  coloured  corpuscles, 
both  when  seen  flat  and  edgeways,  and  the  nucleus  within  each. 

Measure  ten  corpuscles,  and  from  the  results  obtain  the  average  dimen- 
sions of  the  newt's  blood-corpuscle. 

Notice  also  the  colourless  corpuscles,  smaller  than  the  red,  but  consider- 
ably larger  than  the  pale  corpuscles  of  human  blood,  although  otherwise  re- 
sembling these. 

Sketch  two  or  three  red  corpuscles  and  as  many  white. 

Be  careful  not  to  mistake  the  liberated  nuclei  of  crushed  red  corpuscles 
for  pale  corpuscles. 

Enormous  cells  and  nuclei  belonging  to  the  cutaneous  glands  as  well  as 
the  granular  secretion  of  those  glands  may  be  present  in  this  preparation. 

2.  Apply  a  drop  of  water  to  the  edge  of  the  cover-glass  of  the  same  pre- 
paration and  notice  its  action  upon  the  corpuscles. 

Sketch  two  or  three  corpuscles  altered  by  the  action  of  the  water. 

3.  Mount  another  drop  of  blood,  and  apply  dilute  acetic  acid  (1  per  cent.) 
instead  of  water  at  the  edge  of  the  cover-glass.  Make  sketches  showing  the 
effect  of  the  acid  upon  both  red  and  white  corpuscles. 

4.  Examine  the  corpuscles  of  newt's  blood  which  has  been  allowed  to 
flow  into  boracic  acid  solution  (2  per  cent.).  Notice  the  effect  produced  upon 
the  coloured  corpuscles.     Sketch  one  or  two. 


The  coloured  blood-corpuscles  of  amphibia  ( fig.  13),  as  well  as  of  most 
vertebrates  below  mammals,  are  biconvex  elliptical  disks,  considerably 
larger  than  the  biconcave  circular  disks  of  mammals.1  In  addition  to 
the  coloured  body  of  the  corpuscle,  which  consists,  as  in  mammals,  of 
haemoglobin  and  stroma,  there  is  a  colourless  nucleus,  also  of  an  ellip- 
tical shape,  but  easily  becoming  globular,  especially  if  liberated  by  any 
means  from  the  corpuscle.  The  nucleus  resembles  that  of  other  cells 
in  structure,  being  bounded  by  a  membrane,  and  having  a  network  of 
filaments  traversing  its  interior  (fig.  14).  It  is  not  very  distinct  in 
the  unaltered  corpuscle,  but  is  brought  clearly  into  view  by  the  action 

1  The  following  are  the  dimensions  in  parts  of  a  millimeter  of  some  of  the 
corpuscles  of  oviparous  vertebrates  : — 


Long  diameter 

Short  diameter 

Pigeon 

.     0-0147 

0-0065 

Frog  . 

.     0-0223 

00157 

Newt . 

.     0-0293 

0-0195 

Proteus 

.     0-058 

0-035 

Amphiuma 

.     0-077 

0-04(3 

STUDY  OF   THE   BLOOD-CORPUSCLES   OF  AMPHD3L4. 


15 


of  reagents,  especially  acetic  acid.  The  action  of  reagents  upon  the 
red  corpuscle  of  amphibia  is  otherwise  similar  to  that  produced  upon 
the  mammalian  corpuscle,  water  and  acetic  acid  causing  it  to  swell 
into  a  globular  form  and  then  to  become  decolorised  ;  solution  of  salt 
causing  a  shrinking  of  the  corpuscle,  and  so  on.  Boracic  acid  acts 
like  tannic  acid  in  causing  the  haemoglobin  to  be  withdrawn  from  the 
stroma ;  but  it  becomes  partially  or  wholly  collected  around  the 
nucleus,  which  may  then  be  extruded  from  the  corpuscle. 


Fig.  13. — Frog's  Blood.    (Ranvier.) 

a,  red  corpuscle  seen  on  the  flat ;  r,  vacuoles  in  a  cor- 
puscle ;  b,  c,  red  corpuscles  in  profile;  n,  pale  cor- 
puscle at  rest ;  m,  pale  corpuscle,  exhibiting  amoeboid 
movements  ;  p,  coloured  fusiform  corpuscle. 


Fig.  14. — Coloured 
corpuscle  of  sa- 
lamander, show- 
ing intranuclear 
network.  (Flem- 
ming.) 


The  colourless  corpuscles  (fig.  13,  k,  m,  n),  although  larger,  are 
very  similar  to  those  of  mammals.  Like  them,  they  are  of  two  kinds 
— either  wholly  pale  or  enclosing  a  number  of  dark  granules.  They 
vary  much  in  size  and  in  the  activity  of  their  amoeboid  movements. 
They  may  have  one  or  several  nuclei.  Reagents  have  the  same  effect 
upon  them  as  on  those  of  mammals. 


16  THE    ESSENTIALS   OF   HISTOLOGY 


LESSON   V. 

THE  AMCEBOID  PHENOMENA    OF  THE   COLOURLESS 
BLOOD-CORP  USCLES. 

1.  Make  a  preparation  of  blood  froni  the  finger  in  the  usual  way.  Draw 
a  brush  just  moistened  with  oil  around  the  edge  of  the  cover-glass  to  check 
evaporation.  Place  the  preparation  upon  a  -warm  stage,'  and  heat  this  to 
about  the  temperature  of  the  ody  (38°  C).  Bring  a  white  corpuscle  under 
observation  with  the  high  power,  and  watch  the  changes  of  shape  which  it 
undergoes.  To  become  convinced  of  these  alterations  in  form,  make  a  series 
of  outline  sketches  of  the  same  corpuscle  at  intervals  of  a  minute. 

The  simplest  form  of  '  warm  stage  '  is  a  thin  copper  plate  of  about  the  size 
of  an  ordinary  slide,  perforated  in  the  centre  and  with  a  long  tongue  of  the  same 
metal  projecting  from  the  middle  of  one  edge  (fig.  15).  The  copper  plate  is 
firmly  cemeuted  with  sealing-wax  to  a  glass  slide  which  rests  upon  the  stage 


Fig.  15. — Simple  warming  apparatus,  complete,  shown  in  operation. 

of  the  microscope.  The  preparation,  which  should  be  made  upon  a  rather 
thin  slip  of  glass,  is  put  on  to  the  warm  stage  and  pressed  into  contact  with 
it  by  the  brass  clips.  Heat  is  applied  to  the  copper  tongue  by  a  small  spirit- 
lamp  flame,  and  a  greater  or  less  amount  is  conducted  to  the  warm  stage 
and  the  superjacent  preparation  according  to  the  point  to  which  the  flame  is 


AMCEBOID  PHENOMENA   OF   COLOURLESS   CORPUSCLES      17 

applied.  To  ascertain  that  the  right  temperature  is  got  and  maintained,  put 
two  pieces  of  paraffin,  one  melting  at  35°  C.  i(J.33  F.)  and  another  at  38°  C. 
(100°  F.),  on  the  slide,  one  on  either  side  of  the  preparation.  The  tempera- 
ture must  be  such  that  the  first  piece  is  melted  and  remains  so  whilst  the 
second  remains  solid.1 

2.  Mount  a  drop  of  newt's  blood  diluted  with  an  equal  amount  of  salt 
solution,  and  examine  it  in  the  same  manner  upon  the  copper  stage ;  the 
temperature  must,  however,  be  kept  below  30°  C.  Observe  the  effect  of  heat 
in  accelerating  the  amoeboid  movements  of  the  pale  corpuscles.  Sketch  one 
at  intervals  of  a  minute  (a)  in  the  cold,  (6)  whilst  warmed. 

3.  Examine  some  yeast  which  has  been  mixed  with  salt  solution.  Observe 
the  yeast-cells  or  torulae,  some  of  them  budding.     Sketch  two  or  three. 

Now  mix  a  little  of  the  yeast  and  salt  solution  with  a  fresh  drop  of  newt's 
blood,  oiling  the  edge  of  the  cover-glass  as  before.  Endeavour  to  observe  the 
inception  of  torulae  by  the  white  corpuscles.  Sketch  one  or  two  corpuscles 
containing  torulae. 

Milk-globules  or  particles  of  carbon  or  of  vermilion  may  also  be  used  for 
this  experiment,  but  the  process  of  inception  is  most  readily  observed  with 
the  yeast  particles. 

4.  At  the  commencement  of  the  lesson  collect  a  drop  of  newt's  blood  into 
a  fine  capillary  tube,  seal  the  ends  of  the  tube,  and  mount  it  in  a  drop  of  oil 
of  cloves.  Towards  the  end  of  the  lesson  examine  it  again  to  see  white  cor- 
puscles emigrating  from  the  shrunken  clot  (see  fig.  16). 


Fio.  10. — White  cobpi  scles  oi    i  roc's  blood  migrated  from  shrunken 

CLOT   within   A   CAPILLARY   TUBE. 

1  For  exact  work,  an  apparatus  somewhat  more  complex  than  the  above  is  re- 
quired.  For  description  of  such  a  one  see  A  Course  ofPractit  al  Histology,  pp.  22,  2  I 

C 


18  THE   ESSENTIALS   OF  HISTOLOGY 

The  amoeboid  phenomena  which  are  exhibited  by  the  protoplasm  of 
the  colourless  blood-corpuscles  consist,  in  the  first  place,  of  spontaneous 
changes  of  form,  which  when  active  may  also  produce  changes  in  place 
or  actual  locomotion  (migration)  of  the  corpuscle  ;  and,  secondly,  of  a 
tendency  which  it  presents  to  enwrap  and  take  into  its  substance 
foreign  particles  with  which  it  may  come  in  contact,  and  particles  thus 
incepted  may  then  be  conveyed  by  the  corpuscle  in  its  locomotory 
changes  from  one  place  to  another. 

It  is  probable  that  particles  of  organic  matter  which  are  taken  up 
by  the  pale  corpuscles  may  undergo  some  slow  process  of  intracellular 
digestion  within  their  protoplasm. 

The  processes  of  the  granular  corpuscles  are  generally  quite  clear 
at  first,  and  the  granules  afterwards  flow  into  them. 

The  migration  of  the  colourless  corpuscles  from  the  blood-vessels 
into  the  surrounding  tissue,  or  from  a  blood-clot  into  the  surrounding 
serum  (fig.  16),  is  owing  to  these  amoeboid  properties. 

The  conditions  which  are  most  favourable  to  this  amoeboid  activity 
of  the  white  corpuscles  are  (1)  the  natural  slightly  alkaline  medium, 
such  as  plasma,  serum,  or  lymph,  or,  failing  these,  normal  saline 
solution  ;  (2)  the  prevention  of  desiccation.  Any  increase  of  density 
of  the  medium  produces  a  diminution  of  amoeboid  activity,  whilst,  on 
the  other  hand,  a  slight  decrease  in  its  density  has  the  opposite  effect ; 
(3)  a  certain  temperature.  In  warm-blooded  animals  the  phenomena 
cease  below  about  10°  C.  When  gradually  warmed  they  become  more 
and  more  active  up  to  a  certain  point,  the  maximum  being  a  few 
degrees  above  the  natural  temperature  of  the  blood.  Above  this  point 
they  become  spheroidal  and  their  protoplasm  is  coagulated  and  killed. 
Acids  at  once  kill  the  corpuscles  and  stop  the  movements.  Narcotic 
gases  and  vapours,  such  as  carbonic  acid  gas  or  chloroform  vapour, 
also  arrest  the  movement,  but  it  recommences  after  a  time  if  their 
action  is  discontinued. 


19 


LESSON  VI. 

EPITHELIUM. 

1.  Mount  a  drop  of  saliva  and  examine  first  with  a  low,  afterwards  with  the 
high  power.  Observe  the  nucleated  epithelium-cells,  some  single,  and  others 
still  adhering  together  by  overlapping  edges.  Measure  three  or  four,  and  also 
their  nuclei.  Sketch  one  or  two  on  the  flat  and  one  edgeways.  Notice  the 
salivary  corpuscles,  which  are  like  white  blood-corpuscles  swollen  out  by 
imbibition  of  water. 

2.  Put  a  small  shred  of  human  epidermis  into  a  drop  of  strong  caustic 
potash  solution  for  one  or  two  minutes.  Then  break  it  up  hi  water  with 
needles,  cover  and  examine.  Observe  the  now  isolated  swollen  cells. 
Measure  some. 

3.  Study  the  arrangement  of  the  cells  in  a  section  through  some  stratified 
epithelium,  such  as  that  of  the  mouth,  skin,  or  cornea.  The  section  may  be 
prepared  beforehand  by  the  demonstrator ;  it  should  be  mounted  in  Canada 
balsam.1  Notice  the  changes  in  shape  of  the  cells  as  they  are  traced  towards 
the  free  surface.  Measure-  the  thickness  of  the  epithelium.  Count  the 
number  of  layers  of  cells. 

4.  Study  the  minute  structure  of  epithelium-cells  and  their  nuclei,  both 
at  rest  and  dividing,  hi  the  tail  of  the  salamander-tadpole.2  This  preparation 
may  also  advantageously  be  prepared  beforehand  by  the  demonstrator. 

[The  preparation  is  made  as  follows :  The  tail  is  placed  in  chromic  acid 
solution  (0-l  per  cent.)  for  three  days,  then  thoroughly  washed  for  some  hours 
in  water  to  remove  the  excess  of  the  acid,  then  placed  in  dilute  hematoxylin 
solution  for  twenty-four  hours,  or  in  1  p.  c.  safranin  solution  for  a  similar 
time.  After  having  been  again  rinsed  in  water  it  is  rapidly  dehydrated 
in  absolute  alcohol,  then  transferred  to  spirits  of  turpentine,  and  finally 
mounted  in  Canada  balsam.] 

Sketch  an  epithelium-cell  with  resting  nucleus,  and  others  with  nuclei  in 
different  phases  of  karyornitosis. 


An  Epithelium  is  a  tissue  composed  entirely  of  cells  separated  by  a 
very  small  amount  of  intercellular  substance  (cement  substance i,  and 
generally  arranged  so  as  to  form  a  membrane  covering  either  an  ex- 
ternal or  an  internal  free  surface. 

The  structure  of  epithelium-cells,  and  the  changes  which  they 
undergo  in  cell-division,  are  best  seen  in  the  epidermis  of  the  tail  of 
the  salamander-tadpole,  in  which  the  cells  and  nuclei  are  much  larger 
than  in  mammals. 

1  The  methods  of  preparing  sections  are  given  in  the  Appendix. 

•  If  these  tadpoles  are  not  obtainable,  the  structure  may  be  studied  in  the 
epidermis  of  the  newt,  prepared  as  recommended  in  Lesson  VII.  §  1  for  the  study 
of  columnar  epithelium,  and  also  in  sections  stained  with  hematoxylin. 

c2 


20 


THE   ESSENTIALS  OF  HISTOLOGY 


Structure  of  the  cells. — Each  cell  consists  of  protoplasm  containing 
a  nucleus.  The  protoplasm  may  be  either  clear  or  granular,  or  it  may- 
have  a  reticulated  appearance.  In  some  kinds  of  epithelium  it  is 
striated.  The  nucleus  is  a  round  or  oval  vesicle  lying  hi  the  proto- 
plasm. Usually  there  is  only  one,  but  there  may  be  two  or  more  in  a 
cell.  In  the  resting  condition  ( i.e.  when  not  undergoing  division  |  the 
nucleus  is  composed  of  a  membrane  enclosing  a  clear  substance,  which 
is  traversed  by  a  network  of  filaments  (fig.  17,  a).     There  may  be  one 


Fig.  17. — Epithelium-cells  of  salamander  larva  in  different  phases 
ok  division. 


or  more  globular  enlargements  [nucleoli]  on  this  network.  The  nucleus 
is  stained  more  easily  by  dyes  than  the  protoplasm  ;  this  staining 
affects  chiefly  the  nucleoli,  nuclear  filaments,  and  membrane. 

Division  of  the  cells. — The  division  of  a  cell  is  preceded  by  the 
division  of  its  nucleus.  This,  in  dividing,  passes  through  a  series  of 
remarkable  changes  (fig.  17),  which  may  thus  be  briefly  summarised: — 

1.  The  network  of  filaments  of  the  resting  nucleus  becomes  trans- 


EPITHELIUM 


21 


formed  into  a  sort  of  skein,  formed  apparently  of  one  long  convoluted 
filament ;  the  nuclear  membrane  and  the  nucleoli  disappear  or  are 
merged  into  the  skein  (fig.  17,  b,  c,  d). 

2.  The  skein  becomes  arranged  in  the  form  of  a  rosette,  the  fila- 
ments looping  in  and  out,  to  and  from  the  centre  (e). 

3.  The  outer  loops  of  the  rosette  separate,  so  that  the  filament 
breaks  into  a  number  of  V-shaped  fibres  arranged  like  a  star  [aster, 
f,  g,  h.) 

4.  The  V-shaped  fibres  separate  into  two  groups,  the  ends  of  which 
for  a  time  are  interlocked  (i,  j,  k). 

5.  The  two  groups  pass  to  the  opposite  poles  of  the  now  elongated 
nucleus  and  form  a  star-shaped  figure  (Z)  at  each  pole  (dyaster).  Each 
of  the  stars  represents  a  daughter  nucleus. 

6.  7,  8.  Each  star  of  the  dyaster  goes  through  the  same  changes  as 
the  original  nucleus,  but  in  the  reverse  order — viz.  rosette  (mi,  skein 
On,  and  network  (o,  p,  q) ;  passing  finally  into  the  condition  of  a  typi- 
cal resting  nucleus.  The  protoplasm  of  the  cell  divides  soon  after  the 
formation  of  the  dyaster  (m).  Sometimes  fine  lines  maybe  seen  in 
the  protoplasm,  during  the  process  of  division,  radiating  from  the  poles 
of  the  nucleus,  and  others  uniting  the  two  daughter  nuclei. 

Classification  of  epithelia. — Epithelia  are  classified  according  to 
the  shape  and  arrangement  of  the  component  cells.  Thus  we  speak 
of  scaly  or  pavement,  cubical,  columnar,  polyhedral,  and  spheroidal 
epithelium.  All  these  are  simple  epithelia,  with  the  cells  only  one 
layer  deep.  If  forming  several  superposed  layers,  the  epithelium  is 
said  to  be  stratified,  and  then  the  shape  of  the  cells  differs  in  the  dif- 
ferent layers.  Where  there  are  only  three  or  four  layers  in  a  stratified 
epithelium,  it  is  termed  transitional.  . 

Stratified  Epithelium  covers  the  anterior  surface  of  the  cornea, 
lines  the  mouth,  pharynx  (lower  part),  and  gullet,  and  forms  the  epi- 
dermis which  covers  the  skin.     In  the  female  it  lines  the  vagina  and 


~?*l 


Fig.  18. — Section  of  thk  stratified  epithelium  covering  the  front  ok 

THE   CORNEA   OF   Till.    EYE. 
c,  lowermost  columnar  cells  ;  />,  polygonal  cells  above  these  ;  fl,  flattened  cells  near  ti. 


part  of  the  uterus.     The  cells  nearest  the  surface  are  always  flat 
and  scale-like  (fig.  18,  fl ;  fig.  19),  whereas  the  deeper  cells  are  nioie 


29  THE   ESSENTIALS   OF   HISTOLOGY 

rounded  or  polyhedral,  and  those  of  the  deepest  layer  generally  some- 
what columnar  in  shape  (fig.  18,  c).  Moreover,  the  deeper  cells  are 
soft  and  protoplasmic,  and  are  separated  from  one  another  by  a  system 
of  intercellular  channels,  which  are  bridged  across  by  numerous  pro- 
cesses passing  from  cell  to  cell. 

The  deeper  cells  multiply  by  division,  the  newly  formed  cells  tending 
as  they  enlarge  to  push  those  external  to  them  nearer  to  the  surface, 
from  which  they  are  eventually  thrown  off.  As  they  approach  the 
surface  they  become  hard  and  horny,  and  in  the  case  of  the  epidermis 
lose  entirely  their  cellular  appearance,  which  can,  however,  be  in  a 
measure  restored  by  the  action  of  potash  (§  2).  The  cast-off  super- 
ficial cells  of  the  stratified  epithelium  of  the  mouth,  which  are  seen  in 
abundance  in  the  saliva  (§  1),  are  less  altered,  and  the  remains  of  a 
nucleus  is  still  visible  in  them. 


Fig.  19. — Epithelium-scales  from  the      Fig.  20.  —  Pavemext-efithelum   from 
inside  of  the  mouth.   (Magnified  260  A  serous  membrane.     (Magnified  410 

diameters.)  diameters. ) 

a,  cell ;  b,  nucleus  ;  c,  nucleoli. 

Simple  scaly  or  pavement  epithelium  is  found  in  the  saccules  of 
the  lungs,  in  those  of  the  mammary  gland  when  inactive,  in  the  kidney 
(in  the  tubes  of  Henle),  and  also  lining  the  cavities  of  serous  mem- 
branes (fig.  20),  and  the  heart,  blood-vessels,  and  lymphatics.  When 
occurring  on  internal  surfaces,  such  as  those  of  the  serous  membranes, 
blood-vessels,  and  lymphatics,  it  is  often  spoken  of  as  endothelium. 

Polyhedral  or  spheroidal  epithelium  is  characteristic  of  many 
secreting  glands ;  columnar  and  ciliated  epithelium  are  for  the  most 
part  found  covering  the  inner  surface  of  mucous  membranes,  which 
are  membranes  lining  passages  in  communication  with  the  exterior, 
such  as  the  alimentary  canal  and  the  respiratory  and  generative 
passages. 

The  detailed  study  of  most  of  these  may  be  reserved  until  the 
organs  in  which  they  occur  are  respectively  dealt  with. 

The  hairs  and  nails  and  the  enamel  of  the  teeth  are  modified 
epithelial  tissues. 


23 


LESSON  VII. 

COLUMN AE   AXD   CILIATED  EPITHELIUM,    AXD 
TRANSITION  A  L  E  PIT  HE  L I UM. 

1.  Take  a  piece  of  rabbit's  intestine  which  has  been  two  days  in  chromic 
acid  solution  (1  part  chromic  acid  to  2.000  normal  salt  solution).  Scrape  the 
inner  surface  with  a  scalpel,  break  up  the  scrapings  in  a  chop  of  water  on  a 
slide.  Add  a  small  piece  of  hair  to  avoid  crushing,  and  cover  the  preparation. 
Sketch  one  or  two  columnar  cells  and  also  a  row  of  cells.  Measure  two  or 
three  cells  and  their  nuclei. 

To  keep  this  preparation,  add  a  drop  of  dilute  haernatoxylin  (1  drop  of  the 
ordinary  solution  to  half  a  watch-glass-ful  of  distilled  water)  at  one  edge  of  the 
cover-glass.  When  the  hematoxylin  has  passed  in  and  has  stained  the  cell- 
nuclei,  place  a  drop  of  glycerine  at  the  same  edge,  and  allow  it  slowly  to  diffuse 
under  the  cover-glass.    Cement  this  another  day.1 

2.  Break  up  in  glycerine  a  shred  of  epithelium  from  a  piece  of  frog's 
intestine  that  has  been  treated  with  osrnic  acid,  and  has  subsequently 
macerated  in  water  for  a  few  days.  The  cells  easily  separate  on  tapping  the 
cover-glass.  They  are  larger  than  those  of  the  rabbit  and  exhibit  certain 
points  of  structure  better.     Measure  and  sketch  one  or  two  cells. 

The  cover-glass  may  be  at  once  fixed  by  gold  size. 

3.  Prepare  the  ciliated  epithelium  from  a  trachea  that  has  been  in 
bichromate  of  potash  solution  (£per  cent.)  for  two  days,  in  the  same  way  as  in 
§  1.  Measure  in  one  or  two  of  the  cells  (a)  the  length  of  the  cell.  (6  the 
length  of  the  cilia,  [c)  the  size  of  the  nucleus.     Sketch  two  or  three  cells. 

This  preparation  is  to  be  stained  and  preserved  as  in  §  1. 

4.  Make  a  similar  teased  preparation  of  the  epithelium  of  the  urinary 
bladder.  Observe  the  large  flat  superficial  cells,  and  the  pear-shaped  cells 
of  the  second  layer.     Measure  and  sketch  one  or  two  of  each  kind. 

Stain  and  preserve  as  in  §§  1  and  3. 


Columnar  epithelium. — The  cells  of  a  columnar  epithelium  (fig.  21 ) 
are  prismatic  columns,  which  are  set  closely  side  by  side,  so  that  when 
seen  from  the  surface  a  mosaic  appearance  is  produced.  They  often 
taper  somewhat  towards  their  attached  end,  which  is  generally  trun- 
cated, and  set  upon  a  basement  membrane.  Their  free  surface  is 
covered  by  a  thick  striated  border  (fig.  22,  str),  which  may  some- 
times become  detached  in  teased  preparations.  The  protoplasm  of 
the  cell  is  highly  vacuolated  or  reticular,  and  fine  longitudinal  stria? 
may  be  seen  in  it,  which  appear   continuous  with  the  stria3  of  th* 

1  Gentian-violet  solution  (see  Appendix)  maybe  employed  instead  of  ha-ma 
toxylin. 


24 


THE  ESSENTIALS  OF  HISTOLOGY 


free  border.  The  nucleus  (ri)  is  oval  and  reticular.  The  lateral 
borders  of  the  cells  are  often  somewhat  irregular  or  jagged,  the 
result  of  the  pressure  of  amoeboid  lymph-cells,  which  are  generally 
found  between  the  columnar  cells,  at  least  in  the  intestine.     After  a 


Fig.  21. A  row  of  columnar  cells  from  the  intestine  of  the  rabbit. 

Smaller  cells  are  seen  between  the  epithelium-cells,  probably  of  the  nature  of  white  blood  or  lymph 

corpuscles. 

meal  containing  much  fat  the  cells  may  be  filled  with  fat-globules, 
which  become  stained  black  in  the  osmic  preparation. 

Some  of  the  columnar  cells  contain  mucigen,  which  may  greatly 
distend  the  part  of  the  cell  nearest  the  striated  border.     When  the 


tr,-s 


Fig.  22. — Columnar  epithelium-cells  of  thi?  rabbit's  intestine. 

The  cells  have  been  isolated  after  maceration  in  very  weak  chromic  acid.  The  cells  are  much 
vacuolated,  and  one  of  them  has  a  fat-globule  near  its  attached  end;  the  striated 
border  (sir)  is  well  seen,  and  the  bright  disk  separating  it  from  the  cell-protoplasm  ; 
n,  nucleus  with  intranuclear  network  ;  a,  a  thinned-out  wing-like  projection  of  the  cell 
which  probably  fitted  between  two  adjacent  cells. 


mucigen  is  extruded  as  mucus,  this  border  is  thrown  off,  and  the  cell 
takes  the  form  of  an  open  cup  or  chalice  (goblet-cell,  fig.  23). 

Columnar  epithelium-cells  are  found  lining  the  whole  of  the  interior 
of  the  stomach  and  intestines  :  they  are  also  present  in  the  ducts  of 
most  glands,  and  sometimes  also  in  their  secreting  saccules.  The  epi- 
thelium which  covers  the  ovary  also  has  a  modified  columnar  shape, 
but  cells  having  all  the  structural  peculiarities  indicated  above  are 
found  only  in  the  alimentary  canal  and  in  its  diverticula. 

Ciliated  epithelium.— The  cells  of  a  ciliated  epithelium  are  also 
usually  columnar  in  shape  (fig.  24),  but  in  place  of  the  striated  border 
the  cell  is  surmounted  by  a  bunch  of  fine  tapering  filaments  which, 


COLUMNAR.  CILIATED,  AXD   TRANSITIONAL   EPITHELIUM     25 

during  life,  move  spontaneously  to  and  fro,  and  serve  to  produce  a 
current  of  fluid  over  the  surface  which  they  cover. 

The  cilia  are  to  be  regarded  as  active  prolongations  of  the  cell- 
protoplasrn.  The  border  upon  which  they  are  set  is  bright,  and 
appears  formed  of  little  juxtaposed  knobs,  to  each  of  which  a  cilium  is 
attached.  In  the  large  ciliated  cells  which  line  the  alimentary  canal 
of  some  molluscs  (fig.  25)  the  knob  may  be  observed  to  be  prolonged 
into  the  protoplasm  of  the  cell  as  a  fine  varicose  filament,  termed  the 
rootlet  of  the  cilium.  These  filaments  may  represent  the  longitudinal 
striae  often  seen  in  the  protoplasm  of  the  columnar  cell,  the  bunch  of 
cilia  being  homologous  with  the  striated  border.  The  protoplasm  and 
nucleus  have  a  similar  vacuolated  or  reticular  structure  in  both  kinds 
of  cell.     Goblet  cells  may  also  occur  in  ciliated  epithelia. 


Fig.  23.— Goblet  cell 


Fig.  24. — Columnar   cili- 
ated EPITHELIUM-CELLS. 


Fig.  25. — Ciliated  cell, 
from    the   intestine 

OF    A    Mdl.  i 


Ciliated  epithelium  is  found  throughout  the  whole  extent  of  the 
air-passages  and  their  prolongations  (but  not  the  part  of  the  nostrils 
supplied  by  the  olfactory  nerves,  nor  in  the  lower  part  of  the  pharynx) ; 
in  the  Fallopian  tubes  and  the  greater  part  of  the  uterus;  in  some  of 
the  efferent  ducts  of  the  testicle  i  where  the  cilia  are  much  longer  than 


26  THE   ESSENTIALS   OF  HISTOLOGY 

elsewhere  in  the  body  i  ;  in  the  ventricles  of  the  brain,  and  the  central 
canal  of  the  spinal  cord  ;  and  in  the  convoluted  tubules  of  the  kidney. 
Transitional  epithelium  is  a  stratified  epithelium  consisting  of 
only  two  or  three  layers  of  cells.  It  occurs  in  the  urinary  bladder, 
the  ureter,  and  the  pelvis  of  the  kidney.  The  superficial  cells  (fig. 
26,  a)  are  large  and  flattened  ;  they  often  have  two  nuclei.     On  their 


Fig.  26. — Epithelial  cells  from  the  bladder  of  the  rabbit.     (Magnified 

500  diameters.) 

a.  large  flattened  cell  from  the  superficial  layer,  with  two  nuclei  and  with  strongly  marked 
ridges  and  intervening  depressions  on  its  under  surface  ;  b,  pear-shaped  cell  of  the  second 
layer  adapted  to  a  depression  on  one  of  the  superficial  cells. 

under  surface  they  exhibit  depressions,  into  which  fit  the  larger  ends 
of  pyriform  cells,  which  form  the  next  layer  (fig.  2G,  b).  Between 
the  tapered  ends  of  the  pyriform  cells  one  or  two  layers  of  smaller 
polyhedral  cells  are  found. 


27 


LESSON   VIII. 

STUDY  OF  CILIA   IN  ACTION. 

1.  Mount  in  sea-water  one  ox-  two  bars  of  the  gill  of  the  marine  rnnssel 
(fig.  27  .  Study  the  action  of  the  large  cilia.  Now  place  the  preparation 
upon  the  copper  warm  stage  Bee  Lesson  V.)  and  observe  the  effect  of  raising 
the  temperature. 

lr  lr 


Fig.  27. — Valve  of  mussel  (mttilus  edulis)  showing  lr,  br.  the  expanded 

GILLS  OB    BRANCHLE,    WHII  II.    OWING     TO    THE     LITTLE    BARS   OF    WHICH    THEY 
ARE   COMPOSED,    PRESENT   A    STRIATED   ASPEI   1. 

ml.  mantle  ;  m,  cut  adductor  ruiuole  ;  i,  mass  of  viscera  :  the  dark  projection  just  above  is  the  foot. 

Keep  this  preparation  until  the  end  of  the  lesson,  by  which  time  many  of 
the  cilia  will  have  become  languid.  When  this  is  the  case  pass  a  drop  of 
dilute  potash  solution  1 1  part  KHO  to  1,000  of  sea-water)  under  the  cover-glass 
and  observe  the  effect. 

2.  Cement  with  sealing-wax  a  piece  of  small  glass  tubing  to  a  slide  so  that 


Fig.  28.— Moist  chamber  adapted  fob  passing  a  gas  or  vapour  to  a 

PREPARATION    UNDER   THE   MICROSCOPE. 

one  end  of  the  tube  comes  nearly  to  the  centre  of  the  slide.     On  this  put  a 
ring  of  putty  or  modelling  wax  half  an  inch  in  diameter  so  as  to  include  the 


28 


THE   ESSENTIALS   OF  HISTOLOGY 


end  of  the  tube,  and  make  a  deep  notch  in  the  ring  opposite  the  tube.  Place 
a  small  drop  of  water  within  the  ring  (fig.  28). 

Put  a  bar  from  the  gill  upon  a  cover-glass  in  the  least  possible  quantity  of 
sea-water;  invert  the  cover-glass  over  the  putty  ring,  and  press  it  gently 
down.  The  preparation  hangs  in  a  moist  chamber  within  which  it  can  be 
studied  through  the  cover-glass,  and  into  which  gases  or  vapours  can  be  passed 
and  their  effects  observed. 

Pass  CO.,  through  the  chamber,  and  after  observing  the  effect  replace  it  by 
air  (see  fig.  29).     Eepeat  with  chloroform  vapour  instead  of  C02. 


The  Movement  of  Cilia. — When  in  motion  a  cilium  is  bent  quickly 
over  in  one  direction  with  a  lashing  whip-like  movement,  immediately 
recovering  itself.  When  vigorous  the  action  is  so  rapid,  and  the 
rhythm  so  frequent,  that  it  is  impossible  to  follow  the  motion  with  the 
eye.     All  the  cilia  upon  a  ciliated  surface  are  not  in  action  at  the  same 


Fig.  29. — Method  of  subjecting  a  preparation  to  a  stream  of  carbonic 

anhydride. 

6,  bottle  containing  marble  and  hydrochloric  acid  :  V  wash-bottle,  connected  by  indiarubber 
tube,  t,  with  the  moist  chamber,  s. 


instant,  but  the  movement  travels  in  waves  over  the  surface.  If  a  cell 
is  detached  from  the  general  surface,  its  cilia  continue  to  act  for  a 
while,  but  at  once  cease  if  they  are  detached  from  the  cell. 

The  rhythm  is  slowed  by  cold,  quickened  by  warmth,  but  heat 
beyond  a  certain  point  kills  the  cells.  The  movement  will  continue 
for  some  time  in  water  deprived  of  oxygen.  Both  CO,  gas  and  chloro- 
form vapour  arrest  the  action,  but  it  recommences  on  restoring  air. 
Dilute  alkaline  solutions  quicken  the  activity  of  cilia,  or  may  even 
restore  it  shortly  after  it  has  ceased. 


20 


LESSON   IX. 

THE  CONNECTIVE  TISSUES. 

AREOLAR   AND   ADIPOSE    TISSUE. 

1.  Take  a  little  of  the  subcutaneous  tissue  or  of  the  intermuscular  connective 
tissue  of  a  rabbit  or  guinea-pig  and  spread  it  out  with  needles  on  a  dry  slide 
into  a  large  thin  film.  Keep  the  centre  moist  by  occasionally  breathing  on 
it,  but  allow  the  edges  to  dry  to  the  slide.  Before  commencing  put  a  drop 
of  salt  solution  on  a  cover-glass,  and  now  invert  this  over  the  film.  Ex- 
amine with  a  high  power.  Sketch  one  or  two  bundles  of  white  fibres  and 
also  one  or  two  elastic  fibres,  distinguishable  from  the  former  by  their 
sharp  outline,  isolated  coiuse,  and  by  then.'  branching.  Sketch  also  one  or 
more  connective-tissue  corpuscles,  if  any  such  are  visible  in  the  clear  inter- 
spaces. Look  also  for  migratory  cells  (lymph-corpuscles).  Next  carefully 
remove  the  cover-glass  and  replace  the  salt  solution  by  dilute  acetic  acid. 
Watch  its  effect  in  swelling  the  white  fibres  and  bringing  more  elearlj-  into 
view  the  elastic  fibres  and  corpuscles.  Look  for  constricted  bundles  of  white 
fibres. 

2.  Make  another  film  in  the  same  way,  but  mount  in  dilute  magenta 
solution  '  instead  of  saline  solution.  The  elastic  fibres  are  deeply  stained  by 
the  dye  ;  the  cells  are  also  well  shown.  When  the  staining  is  completed  pass 
dilute  glycerine  under  the  cover-glass  and  cement  this  at  once  with  gold 
size. 

3.  Prepare  another  film  of  the  subcutaneous  tissue,  including  a  little 
adipose  tissue.  Mount  in  glycerine  and  water,  coloured  by  magenta,  with  a 
piece  of  hah-  under  the  cover-glass  to  keep  this  frorn  pressing  unduly  upon  the 
fat-cells.  Cement  at  once  with  gold  size.  Examine  first  with  a  low  and  after- 
wards with  a  high  power.  The  nucleus  and  envelope  of  the  fat-cell  are  well 
brought  out  by  the  magenta,  and  if  from  a  young  animal,  fat-cells  will  be 
found  in  process  of  formation.    Measure  and  sketch  two  or  three  of  the  cells. 

4.  Spread  out  another  large  film  of  connective  tissue,  letting  its  edges  dry 
to  the  slide.  Place  on  its  centre  a  large  drop  of  nitrate  of  silver  solution 
(1  per  cent.).  After  ten  minutes  wash  this  away  with  distilled  water,  mount 
in  Tarrant  ',  and  expose  to  the  sunlight  until  stained  brown.  Sketch  the  out- 
lines of  two  or  three  of  the  cell-spao    , 


The  connective  tissues  include  areolar  tissue,  adipose  tissue,  clastic 
tissue,  fibrous  tissue,  ret  if  or  m  and  lymphoid  tissue,  cartilage  and  bone. 
All  these  tissues  agree  in  certain  microscopical  and  chemical  charac- 
ter-. They,  for  the  most  part,  have  a  large  amount  of  intercellular 
substance  in  which  fibres  are  developed,  and  these  fibres  are  of  two 

1  See  Appendix. 


30 


THE   ESSENTIALS   OF   HISTOLOGY 


kinds — white  and  yellow  or  elastic.  Moreover,  there  are  many  points 
of  similarity  between  the  cells  which  occur  in  these  several  tissues  ; 
they  are  also  developed  from  the  same  embryonic  formation,  and  they 
tend  to  pass  imperceptibly  the  one  into  the  other.  Besides  this, 
their  use  is  everywhere  similar;  they  serve  to  connect  and  support 
the  other  tissues,  performing  thus  a  passive  mechanical  function. 
They  may  therefore  be  grouped  together,  although  differing  consider- 
ably in  external  characters.  Of  tbese  connective  tissues,  however, 
there  are  three  which  are  so  intimately  allied  as  to  be  naturally  con- 
sidered together,  being  composed  of  exactly  the  same  elements,  although 
differing  in  the  relative  development  of  those  elements  ;  these  are  the 
areolar,  elastic,  and  fibrous  tissues  (adipose  tissue  may  be  looked  upon 
as  a  special  modification  of  areolar  tissue).  Areolar  tissue  being  the 
commonest  and,  in  one  sense,  the  most  typical,  its  structure  may  be 
considered  first. 

Areolar  tissue. — The  areolar  tissue  presents  to  the  naked  eye  an 
appearance  of  fine  transparent  threads  and  lamina?  which  intercross  in 
every  direction  with  one  another,  leaving  intercommunicating  meshes, 
or  areolae,  between  them.  When  examined  with  the  microscope,  these 
threads  and  fibres  are  seen  to  be  principally  made  up  of  wavy  bundles 
of  exquisitely  fine  transparent  fibres  {white  fibres,  fig.  30).  The  bun- 
dles run  in  different  directions,  and  may  branch  and  intercommuni- 
cate with  one  another ;  but  the  individual  fibres,  although  they  pass 
from  one  bundle  to  another,  never  branch  or  join  other  fibres.     The 


Fig.  31. — Ground  substance  of 
connective  tissue  stained 
by  silver.  (The  cell-spaces 
are  left  white.) 


Fig.  30. — Bundles  of  the  white  fibres  of 
areolar  tissue  partly  unravelled. 


fibres  are  cemented  together  into  the  bundles  by  a  clear  substance 
containing  mucin,  and  the  same  clear  material  forms  also  the  basis  or 
ground-substance  of  the  tissue,  in  which  the  bundles  themselves  course, 
and  in  which  also  the  corpuscles  of  the  tissue  lie  embedded.     This 


THE   CONNECTIVE   TISSUES 


31 


ground-substance  between  the  bundles  can  with  difficulty  be  seen  in 
the  fresh  tissue  on  account  of  its  extreme  transparency  ;  but  it  can  be 
brought  to  view  by  staining  with  nitrate  of  silver,  as  in  §  4.  The  whole 
of  the  tissue  is  thereby  stained  of  a  brown  colour,  with  the  exception  of 
the  spaces  which  are  occupied  by  the  corpuscles  (cell-spaces,  fig.  31). 

Besides  the  white  fibres  of  connective  tissue  here  described,  fibres 
of  a  different  kind  (fig.  32)  may  be  made  out  in  the  preparations; 


Fig.  32. 

A.  Elastic  fibres  of  areolar  tissue.  From  the  subcutaneous  tissue 
of  the  rabbit.  B  (from  ToMt  >.  A  white  lmn<lle  swollen  by  acetic 
acid.    From  the  subarachnoid  tissue  at  the  base  of  the  brain. 

these  are  the  clastic  fibres.  They  are  especially 
well  seen  after  treatment  with  acetic  acid,  and 
after  staining  with  magenta  ;  but  they  can  be  de- 
tected also  in  the  fresh  preparation.  They  are 
characterised  by  their  distinct  outline,  their  straight 
course,  the  fact  that  they  never  run  in  bundles,  but 
singly,  and  that  they  branch  and  join  neighbouring  fibres.  If  broken 
by  the  needles  hi  making  the  preparation,  the  elastic  recoil  causes 
them  to  curl  up,  especially  near  the  broken  ends.  Besides  the 
microscopical  differences,  the  two  kinds  of  fibres  differ  also  in  their 
chemical  characters.  Thus  the  white  fibres  are  dissolved  by  boiling  in 
water,  and  yield  gelatin  ;  whereas  the  substance  of  which  the  elastic 
fibres  are  composed  (elastin)  resists  for  a  long  time  the  action  of  boil- 
ing water.  Moreover,  the  white  fibres  swell  and  become  indistinct 
under  the  action  of  acetic  acid  ;  the  elastic  fibres  are  unaltered  by  this 
reagent. 

The  bundles  of  white  fibres  which  have  been  swollen  out  by  acid 
sometimes  exhibit  curious  constrictions  (fig.  32 1.    These  are  due  either 


32 


THE  ESSENTIALS   OF  HISTOLOGY 


to  elastic  fibres  coiling  round  the  white  bundles,  or  to  cell  processes 
encircling  them,  or  to  an  investment  or  sheath  which  remains  un- 
broken at  certain  parts,  and  thus  prevents  the  swelling  up  of  the 
bundle  at  these  places. 

The  cells  of  areolar  tissue  are  generally  flattened  and  more  or  less 
branched  (fig.  33),  but  maybe  of  an  elongated  form.    They  usually  con- 


FlG.   33. — TWO    FLATTENED   AND   BRANCHED   CONNECTIVE-TISSUE   CORPUSCLES 
FROM   THE   SUBCUTANEOUS   AREOLAR    TISSUE. 

Opposite  I  a  secondary  lamella,  projecting  towards  the  observer,  is  seen  in  optical 
section  as  a  dark  line. 

tain  a  single  large  oval  nucleus  having  the  usual  structure  of  cell-nuclei. 
Their  protoplasm  is  generally  much  vacuolated,  and  it  may  also  contain 
granules.     In  the  middle  coat  of  the  eye  the  connective-tissue  cells  are 

filled  with  granules  of  pigment. 

The  cells  lie  in  spaces  in  the 
ground- substance  between  the 
bundles  of  white  fibres.  In  some 
parts  of  the  connective  tissue  the 
white  bundles  are  developed  to 
such  an  extent  as  to  pervade 
almost  the  whole  of  the  ground- 
substance,  and  then  the  con- 
nective-tissue corpuscles  become 
squeezed  into  the  interstices, 
flattened  lamellar  expansions  of 
the  cells  extending  between  the 
bundles,  as  in  tendon  (see  next 
lesson ) .  The  cells  are  frequently 
joined  either  into  a  network  by 
branching  processes  (fig.  34),  or 
edge  to  edge,  like  the  cells  of  an 
epithelium  (fig.  35);  in  either 
case  the  cell-spaces  are  also  con- 
joined equally  intimately. 
Besides  the  flattened,  branched, 
and  elongated  connective-tissue  corpuscles,  others  are  met  with  which 
are  like  very  large  lymph-corpuscles  in  appearance,  and  are  filled  with 
distinct  granules,  which  are  stained  deeply  by  aniline  dyes.  These 
cells  are  very  common  in  the  neighbourhood  of  blood-vessels,  espe- 


Fig.  34.  —  Ramified  connective-tissue 
corpuscles,  from  articular  synovial 
membrane  of  ox. 


AREOLAR    TISSUE 


33 


Fig.  35. — Epithelioid  cell^  of  connective  tissue,  from  the  surface  of 
an  aponeurosis  aftee  treatment  with  nitrate  of  silver..  (the  cell- 
Quclei  are  not  shown.) 


Fn..    36, — A    FEW   ,  ELLS    FROM   THE    MARGIN   OF   A    FAT-LOBULE. 


/'./.  i   •  -  istending  a  fat-cell  :  «.  nucleus  :  m,  membranous  envelope  of  the  fat-cell ; 

e  r,  bunch  of  crystals  withi  -  :    v,  venule;  c  t,  connect. 

tissue  cell ;  the  fibres  of  the  connective  tissue  are  not  represented. 

cially  where  fat  is  becoming  developed  (see  fig.  37 1 ;  they  exhibit  slight 
indications  of  amoeboid  movement,  and  are  known  as  the  plasma-cells. 

Migratory  or  lymph-cells  may  also  be  seen  here  and  there  in  the  tissue. 


34 


THE   ESSENTIALS  OF  HISTOLOGY 


The  branched  cells  and  cell-spaces  of  areolar  tissue  come  into 
intimate  relation  with  the  cells  lining  the  lymphatic  vessels  and  small 
blood-vessels.  This  connection  can  best  be  seen  in  silvered  prepara- 
tions ;  it  will  be  again  referred  to  in  speaking  of  the  origin  of  the 
lymphatics. 

Adipose  tissue  consists  of  vesicles  filled  with  fat  (fig.  36 1,  and  col- 
lected into  lobules  or  into  tracts  which  accompany  the  small  blood- 
vessels. The  vesicles  are  round  or  oval  in  shape,  except  where  closely 
packed,  when  they  become  polyhedral  from  mutual  compression.  The 
fat-drop  is  contained  within  a  delicate  protoplasmic  envelope  (fig.  36, 
vi )  which  is  thickened  at  one  part,  and  here  includes  an  oval  flattened 
nucleus.  The  vesicles  are  supported  partly  by  filaments  of  areolar 
tissue,  but  chiefly  by  a  fine  network  of  capillary  blood-vessels. 

The  fat  when  first  formed  is  deposited  within  plasma-cells  of  areolar 
tissue  (fig.  37).     It  is  at  first  in  separate  droplets  within  each  cell,  but 


Fig.  37. — Deposition  of  fat  r>~  connective-tissue  cells. 

/,  a  cell  with  a  few  isolated  fat-droplets  in  its  protoplasm  :  /"',  a  cell  with  a  single  large  and 
several  minute  drops  ;  /".  fusion  of  two  large  drops ;  g,  granular  or  plasma  cell,  not 
yet  exhibiting  any  fat-deposition ;  c  t,  flat  connective-tissue  corpuscle  ;  c,  c,  network  of 
capillaries. 

as  these  droplets  increase  in  size  they  run  together  into  a  larger  drop, 
which  gradually  fills  the  cell  more  and  more,  swelling  it  out  so  that 
the  cell-protoplasm  eventually  appears  merely  as  the  envelope  of  the 
fat -vesicle. 

Fat  is  found  most  abundantly  in  subcutaneous  areolar  tissue,  and 
under  the  serous  membranes  ;  especially  in  some  parts,  as  at  the  back 
of  the  peritoneum  around  the  kidneys,  under  the  epicardium,  and  in 
the  mesentery  and  omentum.  The  marrow  of  the  long  bones  is  also 
principally  composed  of  fat. 


35 


LESSON  X. 

THE   CONNECTIVE   TISSUES  (continued). 

ELASTIC    TISSUE,   FIBROUS   TISSUE,    SPECIAL   VARIETIES,    DEVELOPMENT 
OF   CONNECTIVE    TISSUE. 

1.  Tease  out  as  finely  as  possible  a  small  shred  of  elastic  tissue  (ligarnentum 
nucha?  of  the  ox  or  liganienta  subflava  of  man)  in  Farrant's  solution1  and 
cover  the  preparation.  Note  the  large  well-defined  fibres  constantly  branching 
and  uniting  with  one  another.  Look  for  transverse  markings  on  the  fibres. 
Measure  three  or  four.  Sketch  a  small  part  of  the  network.  Note  the 
existence  of  bundles  of  white  fibres  amongst  the  elastic  fibres. 

2.  Mount  in  Farrant  a  thin  transverse  section  of  ligarnentum  nucha? 
which  has  been  hardened  in  2  per  cent,  solution  of  bichromate  of  potash. 
Observe  the  grouping  of  the  fibres  and  then  angular  shape.  Sketch  one  or 
two  groups. 

3.  Pinch  off  the  end  of  the  tail  of  a  dead  mouse  or  rat,  draw  out  the  long 
silk-like  tendons  and  put  them  into  saline  solution.  Take  two  of  the  longest 
threads  and  stretch  them  along  a  slide,  letting  the  ends  dry  firmly  to  the  slide 
but  keeping  the  middle  part  moist.  Put  a  piece  of  hair  between  them  and 
cover  in  saline  solution.  Observe  with  a  high  power  the  fine  wavy  fibrillation 
of  the  tendon.  Draw.  Now  run  dilute  acetic  acid  under  the  cover-glass, 
watch  the  tendons  where  they  are  becoming  swollen  by  the  acetic  acid. 
Notice  the  oblong  nucleated  cells  coming  into  view  between  the  tendon 
bundles.  Sketch  three  or  four  cells  in  a  row.  Lastly,  lift  the  cover-glass, 
wash  away  the  acid  with  distilled  water,  place  a  drop  of  hematoxylin  solution 
on  the  tendons,  and  leave  the  preparation  for  fifteen  minutes  or  more  ;  then 
wash  away  the  logwood  and  mount  the  preparation  in  acidulated  glycerine. 
Cement  the  cover-glass  with  gold  size. 

4.  Immerse  one  or  two  other  pieces  of  tendon  in  nitrate  of  silver  solution 
(1  per  cent.)  for  ten  minutes,  then  wash  them  in  distilled  water,  stretch 
them  upon  a  slide,  mount  in  Farrant,  and  expose  to  the  sunlight. 

5.  Stain  with  magenta  solution '  a  thin  section  of  a  tendon  which  has 
been  hardened  in  alcohol.  Mount  in  dilute  glycerine  and  cement  the  cover- 
glass  at  once.     Sketch  a  portion  of  the  section  under  a  low  power. 


Elastic  tissue  is  a  variety  of  connective  tissue  in  which  the  elastic 
fibres  preponderate.  It  is  found  most  characteristically  in  the  liga- 
rnentum nuclne  of  quadrupeds  and  the  liganienta  subflava  of  the 
vertebra,  but  the  connective  tissue  of  other  parts  may  also  have  a  con- 

1  See  Appendix. 


36  THE    ESSENTIALS   OF   HISTOLOGY 

siderable  development  of  elastic  fibres.  It  occurs  also  in  an  almost 
pure  form  in  the  walls  of  the  air-tubes,  and  uniting  the  cartilages  of 
the  larynx.  It  also  enters  largely  into  the  formation  of  the  walls  of 
the  blood-vessels,  especially  the  arteries. 

In  the  ligamentum  nuchas  the  fibres  are  very  large  and  angular 
(fig.  38) ;  they  often  exhibit  cross-markings  or  even  transverse  clefts. 
When  dragged  asunder,  they  break  sharply  across  ;  they  constantly 
branch  and  unite,  so  as  to  form  a  close  network.  In  transverse 
section  they  are  seen  to  be  separated  into  small  groups  (fig.  39)  by 
intervening  white  bundles  of  connective  tissue. 


<S=>f 


**L*% 


mm*? 


G> 


CD 


Fig.  39. — Cross-section  of  elastic 
fibres  from  the  ligamentum 
nuch.e  of  the  ox. 


Fig.  38. — Elastic  fibres  from  the  liga- 
mentum NUCH.E  OF  THE  OX,  SHOWING 
TRANSVERSE    MARKINGS   ON    THE    FIBRES. 


Elastic  tissue  does  not  always  take  the  form  of  fibres,  but  may 
occur  as  membranes  (as  in  the  blood-vessels).  Sometimes  the  fibres 
are  very  small,  but  their  microscopical  and  chemical  characters  are 
always  very  well  marked  (see  p.  31). 

Fibrous  tissue  is  almost  wholly  made  up  of  bundles  of  white  fibres 
running  in  a  determinate  direction.  These  again  are  collected  into 
larger  bundles,  which  give  the  fibrous  appearance  to  the  tissue.  The 
bundles  are  constantly  uniting  with  one  another  in  their  course,  although 
their  component  fibres  remain  perfectly  distinct. 

The  interspaces  between  the  larger  bundles  are  occupied  by  areolar 
tissue  (fig.  40)  in  which  the  blood-vessels  and  lymphatics  of  the  fibrous 


FIBROUS    TISSUE 
,6 


37 


'•■d 


Fig.  40. — Part  of  a  large  tendon*  in  transverse  section. 


a.  areolar  sheath  of  the  tendon,  with  the  fibres  for  the  most  part  running  transversely,  but 

with  two  or  three  longitudinal  bundles,  b ;  '.lymphatic  cleft  in  the  >heath:  immediately 

over  it  a  blood-vessel  is  seen  cut  across,  and  on  the  other  side  of  the  figure  a  small  artery 

iwn  cut  longitudinally  ;  <-.  large  septum  of  areolar  tissue  ;  <',  -mailer  septum ;  e,  still 

smaller  septum.    The  irregularly  stellate  bodies  are  the  tendon  cells  in  section. 


Fig.  41. — Tendon  of  house's  tail,  stained  with  logwood;  showing  chains 

OK   CELLS   BETWEEN   THE   TENDON-BUNDLES.      (175  diameters.) 


Fig.  42. — Transverse  section  op  tendon  of  house's  tail,  stained. 
( 175  diameters.) 

The  flattened  processes  of  the  tendon-cells  appeal  in  section  as  lines,  frequently  coming  off  at 
right  angles  from  the  body  of  the  cell. 


38 


THE   ESSENTIALS   OF   HISTOLOGY 


tissue  are  conveyed.  The  interstices  between  the  smallest  bundles 
are  occupied  by  rows  of  connective-tissue  corpuscles  (tendon-cells), 
which  from  being  squeezed  up  between  three  or  more  bundles  become 
flattened  out  in  two  or  three  directions.  In  transverse  section  the  cells 
appear  somewhat  stellate  (figs.  40,  42),  but  when  seen  on  the  flat 
they  appear  lamellar  (fig.  41 1,  and  from  this  aspect  their  general  shape 
is  square  or  oblong.  They  lie,  as  before  said,  in  rows  between  the 
tendon-bundles,  and  the  nuclei  of  adjacent  cells  are  placed  opposite 


^^AiUfe 


^*^H^^SHK^|BP 


Fig.  43. — Eight  cells  from  the  same  tendon*  as  represented  in  fig.  41. 
(425  diameters.) 

The  nuclei,  with  their  numerous  nucleoli,  are  coloured  by  the  logwood.  The  dark  lines  on 
the  surface  of  the  cells  are  the  optical  sections  of  lamellar  extensions  directed  towards  or 
a "vay  from  the  observer. 

one  another  in  pairs  (fig.  43).     The  cell-spaces  correspond  hi  general 
figure  and  arrangement  to  the  cells  which  occupy  them  (fig.  44 1. 


Fig.  44. — Cell-spaces  of  tendon  of  house's  tail,  brought  into  view  by 
treatment  with  nitrate  of  silver.     (175  diameters.) 


Fibrous  tissue  forms  the  tendons  and  ligaments,  and  also  certain 
membranes,  such  as  the  dura  mater,  the  fibrous  pericardium,  the  fascia? 
of  the  limbs,  the  fibrous  covering  of  certain  organs,  &c.  It  is  found 
wherever  great  strength  combined  with  flexibility  is  concerned.  It 
receives  a  few  blood-vessels,  disposed  longitudinally  for  the  most  part, 
and  contains  many  lymphatics.  Tendons  and  ligaments  also  receive 
nerve-fibres,  which,  in  some  cases,  end  in  small  localised  ramifications 
like  the  end-plates  of  muscle,  while  others  terminate  in  end-bulbs  or  in 
simple  Pacinian  corpuscles. 

Retiform  or  reticular  tissue  is  a  variety  of  connective  tissue  in 
which  the  intercellular  or  ground  substance  has  mostly  disappeared  or 
is  replaced  by  fluid,  very  few  or  no  fibres  having  been  developed  in  it ; 
and  these,  when  present,  are  enwrapped  by  the  cells.  Tbe  tissue  is 
composed  almost  entirely  of  the  cells,  which  are  ramified  and  united 


VARIETIES   OF   CONNECTIVE   TISSUE 


39 


with  one  another  into  a  network  or  sponge-work  by  their  processes  ; 
in  some  cases,  the  cell-nuclei  have  disappeared  (as  at  b,  fig.  45). 


Fig.  45. — Thin  section  from  the  cortical  part  of  a  lymphatic  gland, 

magnified. 

A  network  of  fine  trabeculae  formed  by  retiform  tissue,  from  the  meshes  of  which  the 
lymph-corpuscles  have  been  washed  out,  except  at  c,  where  they  are  left. 


Lymphoid  or  adenoid  tissue  is  retiform  tissue  in  which  the  meshes 
of  the  network  are  largely  occupied  by  lymph-corpuscles.  This  is  by 
far  the  most  common  condition  of  a  retiform  tissue,  and  is  met  with  in 
the  lymphatic  glands  and  allied  structures  (see  Lesson  XXII.  |,  and  also 
in  the  tissue  of  the  alimentary  mucous  membrane,  and  hi  some  other 
situations. 

Basement  membranes  (membranes  propria?  i  are  homogeneous-look- 
ing membranes,  which  are  found  forming  the  surface-layers  of  con- 
nective-tissue expansions  in  many  parts,  especially  where  there  is  a 
covering  of  epithelium,  as  on  mucous  membranes,  in  secreting  glands, 
and  elsewhere.  They  are  generally  formed  of  flattened  connective- 
tissue  cells  joined  together  to  form  a  membrane  ;  but,  in  some  cases, 
they  are  evidently  formed  not  of  cells,  but  of  condensed  ground- 
substance,  and  in  others  they  are  of  an  elastic  nature. 

Jelly-like  connective  tissue,  although  occurring  largely  in  the  em- 
bryo, is  found  only  in  one  situation  in  the  adult — viz.  forming  the 
vitreous  humour  of  the  eye.  It  seems  to  be  composed  entirely  of  soft 
ground-substance,  with  cells  scattered  here  and  there  through  it,  and 
with  very  few  fibres,  or  none  at  all.  These  several  varieties  of  con- 
nective tissue  will  be  more  fully  described  in  connection  with  the 
organs  where  they  occur. 

Development  of  connective  tissue.  Connective  tissue  is  always 
developed  in  the  mesoblast  or  mesoderm  of  the  embryo.  In  those 
parts  of  this  layer  which  are  to  form  connective  tissue,  the  embryonic 
cells  become  separated  from  one  another  by  a  muco-albuminous  semi- 
fluid intercellular  substance  ( ground- substance),  but  the  cells  generally 
remain  connected  by  their  processes.      The  connective-tissue  fibr  -. 


40 


THE  ESSENTIALS   OF  HISTOLOGY 


both  white  and  elastic,  are  deposited  in  this  ground-substance,  the 
elastic  substance  usually  in  the  form  of  granules  (fig.  -17,  g),  which 


^ 


Fig.  46. — Jelly  of  Wharton*. 

r,  ramified  cells  intercommuuicatiug  by  their  branches  :  /.  a  row  of  lymph-cells ; 
*,  fibres  developing  in  the  ground-substance. 

subsequently  become  connected  together  into  elastic  fibres  or  lamina?, 
as  the  case  may  be,  the  white  fibres  appearing  at  first  in  the  form  of 
very  fine  bundles,  which  afterwards  become  gradually  larger  ;  so  that 
in  fibrous  tissue  the  whole  ground- substance  is  eventually  pervaded  by 


Fig.  47. — Development  of  elastic  tissue  by  deposition  of  fine 
granules. 

g,  fibres  being  formed  of  rows  of  'elastin'  granules  ;  ;/.  flat  platelike  expansion  of 
elastic  substance  formed  by  the  fusion  of  'elastin  '  granules. 

them,  and  the  cells  of  the  tissue  become  squeezed  up  into  the  intervals 
between  them.  Before  any  considerable  development  of  fibres  has 
taken  place,  the  embryonic  connective  tissue  has  a  jelly-like  appear- 
ance ;  in  this  form  it  occurs  in  the  umbilical  cord,  where  it  is  known 
as  the  jelly  of  Wharton  (fig.  46). 


41 


LESSON   XI. 

THE   CONNECTIVE   TISSUES   {continued). 

ARTICULAR    CARTILAGE. 

1.  Cut  two  or  three  very  thin  tangential  slices  of  the  fresh  cartilage  of  a  joint, 
mount  them  in  saline  solution  and  examine  with  a  high  power.  Observe  care- 
fully the  form  and  grouping  of  the  cells.  Look  at  the  thin  edge  of  the  section 
for  spaces  from  which  the  cells  have  dropped  out.  Measure  two  or  three 
cells  and  their  nuclei,  and  sketch  one  or  two  groups.  Now  replace  the  saline 
solution  by  water  and  set  the  preparation  aside  for  a  little  while.  On  again 
examining  it,  many  of  the  cartilage-cells  will  be  found  to  have  shrunk  away 
from  then  containing  capsules. 

2.  Make  other  sections  of  the  cartilage  (1)  from  near  the  middle.  (2)  from 
near  the  edge.  Mount  in  magenta  solution,  and  when  stained  add  dilute 
glycerine  and  cement  the  cover-glass.  In  (2)  look  for  branched  cartilage-cells. 
Draw  one  or  two. 

3.  Make  vertical  sections  of  articular  cartilage  from  a  bone  which  has 
been  for  several  days  in  h  per  cent,  chromic  acid  solution,  and  mount  the 
sections  in  Farrant.  Sketch  the  arrangement  of  the  cells  in  the  different 
layers. 

4.  Wash  a  fresh  joint  with  distilled  water ;  drop  1  per  cent,  nitrate  of 
silver  solution  over  it;  after  ten  minutes  wash  away  the  nitrate  of  silver 
and  expose  in  water  to  the  light.  "When  browned,  cut  thin  sections  from 
the  surface  and  mount  in  Farrant.  The  cells  and  cell-spaces  show  white  in 
the  brown  ground-substance.     Draw. 


Cartilage  or  gristle  is  a  translucent  bluish-white  tissue,  firm,  and 
at  the  same  time  elastic,  and  for  the  most  part  found  in  connection 
with  bones  of  the  skeleton,  most  of  which  are  in  the  embryo  at  first 
represented  entirely  by  cartilage.  Two  chief  varieties  of  cartilage  are 
distinguished.  In  the  one,  which  is  termed  hyaline,  the  matrix  or 
ground-substance  is  clear,  and  free  from  obvious  fibres ;  in  the  other, 
which  is  termed  fibro-cartilagc,  the  matrix  is  everywhere  pervaded  by 
connective-tissue  fibres.  When  these  are  of  the  white  variety,  the 
tissue  is  white  fibro-cartilagc  ;  when  they  are  elastic  fibres,  it  is  yellow 
tie  tibro-cartilage. 

Hyaline  cartilage  occurs  principally  in  two  situations — namely 
(1)  covering  the  ends  of  the  bones  in  the  joints,  where  it  is  known  as 
articular  cartilage;  and  (2i  forming  the  rib-cartilages,  where  it  is 
known  as  costal  cartilage.     It  also  forms  the  cartilages  of  the  nose,  the 


42  THE   ESSENTIALS   OF  HISTOLOGY 

external  auditory  meatus,  the  larynx,  and  the  windpipe  ;  in  these  places 
it  serves  to  maintain  the  shape  and  patency  of  the  orifices  and  tubes. 

Articular  cartilage.  The  cells  of  articular  cartilage  are  mostly 
scattered  in  groups  of  two  or  four  throughout  the  matrix  (fig.  48). 
The  latter  is  free   from   fibres,  except  at   the   extreme  edge  of  the 


■ 


,,■■■■:■' 


:■<<&& 

.-'..%) 

Sf§§ 

a  u 

Fig.  48. — Articular  cartilage  from  head  of  metatarsal  bone  of  man 

(OSMIC    ACID   PREPARATION).      The  CELL-BODIES  ENTIRELY  FILL   THE   SPACES 

rx  the  matrix.     (340  diameters.) 

a,  group  of  two  cells  ;  b,  group  of  four  cells  ;  h.  protoplasm  of  cell,  with  g,  iaXty  granules 

n,  nucleus. 

cartilage,  where  the  connective-tissue  fibres  from  the  synovial  mem- 
brane extend  into  it ;  and  here  also  the  cartilage-cells  are  often 
branched,  and  offer  transitions  to  the  branched  connective-tissue  cor- 
puscles of  that  membrane  (transitional  cartilage,  fig.  49).  By  long 
maceration,  however,  some  observers  have  obtained  evidence  of  a 
fibrous  structure  even  in  the  matrix  of  true  hyaline  cartilage.  The 
matrix  immediately  around  the  cartilage-cells  is  often  marked  off  from 
the  rest  by  a  concentric  line  or  lines,  this  part  being  known  as  the 
capsule  of  the  cell.  The  cells  are  bluntly  angular  in  form,  the  sides 
opposite  to  one  another  in  the  groups  being  generally  flattened.  The 
protoplasm  is  very  clear,  but  it  may  contain  droplets  of  fat ;  and  with 
a  high  power  fine  interlacing  filaments  and  granules  have  been 
observed  in  it  (fig.  50 j.     During  life  the  protoplasm  entirely  fills  the 


ARTICULAR   CARTILAGE 


43 


cavity  or  cell- space  which  it  occupies  in  the  matrix ;  but  after  death, 
and  in  consequence  of  the  action  of  water  and  other  agents,  it  tends  to 
shrink  away  from  the  capsule.  The  nucleus  is  round,  and  shows  the 
usual  intranuclear  network. 


4" 


Fig.  49. — Border  of  articular  cartilage  showing      Fig.  50. — A  cartilage-cell 


TRANSITION  OF  CARTILAGE-CELLS  INTO  CONN ECTIVK- 
TI8SUE  i  ORPUSCLES  OF  SYNOVIAL  MEMBRANE.  FROM 
HEAD   OF    METATARSAL   BONE,   HUMAN.       (About   O-A0 

diameters.) 
a,  ordinary  cartilage-cells ;   b,  b,  with  branching  processes. 


IN      THE      LIVING      STATE, 
FROM    THE     SALAMANDER. 

Highly  magnified. 


a 

&E)l3< 

■=;  c 

OE» 

OH 

^e.          aeiE 

'- 

.          — 

.•       **      * 

"1 

I 

1 

-• 

> 

§         | 

■ 

Fig.  51. — Vertical  section  ok  articular  cartilage  covering  the  lower 
end  of  the  tibia,  human.    (Magnified  about  80  diameters.) 

a,  cells  and  cell-groups  Battened  conformably  with  the  surface:  6,  cell -groups  irregularly 
arranged;  e,  cell-groups  disposed  perpendicularly  to  the  surface;  d,  layer  of  calcined 
cartilage ;  e,  bone. 

In  vertical  section  (fig.  51)  the  deeper  cell-groups  (c)  are  seen  to  be 
arranged  vertically  to  the  surface,  the  more  superficial  ones  (a)  parallel 
to  the  surface  ;  whilst  in  an  intermediate  zone  the  groups  are  irregu- 


44 


THE   ESSENTIALS   OF   HISTOLOGY 


larly  disposed  \b).  In  the  deepest  part  of  the  cartilage,  next  the  bone, 
there  is  often  a  deposition  of  calcareous  salts  in  the  matrix  {calcified 
cartilage,  d). 

The  disposition  of  the  cells  of  cartilage  in  groups  of  two,  four,  and 
so  on,  is  apparently  due  to  the  fact  that  these  groups  have  originated 
from  the  division  of  a  single  cell  first  into  two.  and  these  again  into 
two,  and  so  on  (fig.  52).     It  would  seem  that  the  matrix  is  formed  of 


_  ■  .  ...  .   uJ|Ui,.liiu,»Jj.iu,Uj,jAjJl|liiJ. "...,.„„., „t 

Fig.  52. — Plan-  of  the  multiplication  of  cells  of 


ARTILAGE. 


A,  cell  in  its  capsule ;  b,  divided  into  two,  each  with  a  capsule ;  c,  primary  capsule  disap- 
peared, secondary  capsules  coherent  with  matrix;  D,  tertiary  division;  E,  secondary 
capsuks  disappeared,  tertiary  coherent  with  matrix. 


Fig.  53. — Division  of  a  caktilage-cell. 

a-h.  stases  of  division  of  a  cell,  as  seen  in  the  living  cartilage  of  the  salamander  (the  con- 
nection of  the  nuclear  filaments  could  not  be  made  out  in  the  fresh  condition  >.  a,  b.  stel- 
late phase  ;  c,  d,  commencing  separation  of  the  nuclear  filaments  :  the  further  stages  of 
separation  are  not  represented ;  e,  filaments  fully  separated  into  two  groups,  and  a  septum 
beginning  to  be  formed  between  them  :  f,  septum  completed,  seen  to  be  double  and  con- 
tinuous  with  capsules  of  daughter  cells;  g,  h,  further  stages  in  the  formation  of  the 
daughter  nuclei. 

successive  portions,  which  are  deposited  around  each  cartilage-cell  as  the 
so-called  '  capsules,  each  newly  formed  portion  soon  blending  in  its  turn 
witli  the  previously  formed  matrix,  whilst  a  new  capsule  is  formed 
within  it.  The  division  of  the  cartilage-cell,  like  that  of  other  cells, 
is  accompanied  by  a  process  of  karyomitosis. 


45 


LESSON   XII. 

THE   CONNECTIVE   TISSUES   {continued). 

COSTAL    CARTILAGE.       FIBRO-CARTILAGE. 

1.  Make  transverse  and  tangential  sections  of  a  rib-cartilage,  stam  them  with 
ra,  and  mount  in  dilute  glycerine,  cementing  at  once.  Sketch  a  part  of 
a  transverse  section  under  a  low  power  and  a  cell-group  from  one  of  the 
tangential  sections  under  a  high  power.  Notice  especially  the  arrangement 
of  tin-  cells,  somewhat  concentric  near  the  surface  but  radial  near  the  centre. 
The  costal  cartil    s  t'ten  ossified  near  the  middle. 

•1.  Make  sections  of  the  cartilage  of  the  external  ear.     Mount  in  dilute 

glycerine  faintly  coloured  with  magenta.     If  from  the  ox.  notice  the  very 

reticulating   elastic    fibres    in    the  matrix.      Notice  also  the   isolated 

granules  of  elastin,  and  around  the  cartilage-cells  the  area  of  clear  ground- 

substance.     Draw  a  small  portion  of  the  section. 


3.  Mount  a  section  of  the  epiglottis  In  the  same  way. 
network  of  much  liner  fibres. 


Notice  the  closer 


4.  Cut  sections  of  white  fibro-cartilage  (intervertebral  disk),  and  stain 
them  with  dilute  magenta.  Mount  in  dilute  glycerine.  Observe  the  wavy 
fibres  in  the  matrix  and  the  cartilage-cells  lying  in  clear  areas  often  con- 
centrically striated.  Look  for  branched  cartilage-cells.  Sketch  three  or  four 
cells  and  the  adjoining  fibrous  matrix. 


Costal  cartilage. — In  the  costal  cartilages  the  matrix  is  not  always 
so  clear  as  in  the  matrix  of  the  joints,  for  it  often  happens  that  fibres 


Fig.  54.— Si.i  rios  oi    rib-cartilage,  showing  two  cell-groups  ra  a 

SOMEWHAT   FIBROU8-LOOKING   MATRIX. 

become  developed  in  it.     The  cells  are  generally  larger  and  more  an- 
gular than  those  of  articular  cartilage,  and  collected  into  larger  groups 


46 


THE   ESSENTIALS   OF   HISTOLOGY 


(fig.  54).  Near  the  circumference,  and  under  the  perichondrium  or 
fibrous  covering  of  the  cartilage,  they  are  flattened  and  parallel  to  the 
surface,  but  in  the  deeper  parts  they  have  a  more  irregular  or  a  radi- 
ated arrangement.  They  frequently  contain  fat.  The  cartilages  of  the 
larynx  and  windpipe  and  of  the  nose  resemble  on  the  whole  the  costal 
cartilages,  but  the  study  of  them  may  be  deferred  until  the  organs 
where  they  occur  are  dealt  with. 

Elastic  or  yellow  fibro-cartilage  occurs  in  only  a  few  situations. 
These  are,  the  cartilage  of  the  external  ear  and  that  of  the  Eustachian 
tube,  the  epiglottis  and  cartilages  of  Santorini  of  the  larynx,  and  in 
some  animals,  e.g.  the  ox,  the  upper  third  of  the  arytenoids.  The 
matrix  is  everywhere  pervaded  with  well-defined  branching  fibres, 
which  unite  with  one  another  to  form  a  close  network  (fig.  55).    These 


Fig.  55. — Section  of  the  elastic  carti- 
lage ok  the  ear.     (Highly  magnified.) 


■ 


Fig.  56. — Section  of  part  of  the  car- 
tilage of  the  epiglottis. 

a,  cartilage-cell  in  clear  area ;  b.  granular- 
looking  matrix  near  the  middle  of  the  carti- 
lage, the  granular  appearance  being  due 
partly  to  the  fine  reticulum  of  elastic  fibres, 
partly  to  the  presence  of  granules  of  elastic 
substance  in  the  matrix  ;  c,  clearer  matrix 
with  longer  fibres. 


fibres  resist  the  action  of  acetic  acid,  and  are  stained  deeply  by  magenta ; 
they  are  evidently  elastic  fibres.  In  the  ox  they  are  very  large,  but 
smaller  in  man,  especially  in  the  cartilage  of  the  epiglottis  (fig.  56). 
They  appear  to  be  developed  by  the  deposition  of  granules  of  elastin 
in  the  matrix,  which  at  first  he  singly,  but  afterwards  become  joined  to 
form  the  fibres. 

White  fibro-cartilage  is  found  wherever  great  strength  combined 
with  a  certain  amount  of  rigidity  is  required  :  thus  we  frequently  find 
fibro-cartilage  joining  bones  together,  asm  the  case  of  the  intervertebral 
disks  and  other  symphyses.  Fibro-cartilage  is  frequently  employed  to 
line  grooves  in  which  tendons  run,  and  may  also  be  found  in  the  tendons 
themselves.  It  is  also  employed  to  deepen  cup- shaped  articular  sur- 
faces ;  and  in  the  case  of  the  interarticular  cartilages,  such  as  those 
of  the  knee  and  lower  jaw,  to  allow  greater  freedom  of  movement 
whilst  diminishing  the  liability  to  dislocation.    Under  the  microscope 


FIBRO-CARTILAGE 


47 


white  fibro-cartilage  looks  very  like  fibrous  tissue,  but  its  cells  are  car- 
tilage-, not  tendon-,  cells  (fig.  57).    They  are  rounded  or  bluntly  angular 


Fig. 


. — White  fibr<: 


:artilage  FROM  an  intervertebral  disk,  human. 
(Highly  magnified.) 

The  concentric  lines  around  the  cells  indicate  the  limits  of  deposit  of  successire  capsules. 
One  of  the  cells  has  a  forked  process  which  extendi  beyond  the  hyaline  area  surrounding 
the  cell,  amongst  the  fibres  of  the  genera!  matrix. 


and  surrounded  by  a  concentrically  striated  area  of  clear  cartilage-* 
matrix.  In  some  parts  of  the  intervertebral  disk  many  of  the  cells  are 
branched,  and  may  be  looked  upon  as  transitional  forms  to  connective- 
tissue  corpuscles. 


48  THE   ESSENTIALS  OF  HISTOLOGY 


LESSON    XIII. 

BONE  AXD   MARROW. 

1.  In  thin  sections  of  hard  bone  made  by  grinding,  observe  the  Haversian 
canals,  lamellae,  lacunae,  canaliculi,  &c.  Make  a  sketch  hrst  under  a  low  and 
afterwards  under  a  high  power. 

2.  With  fine  forceps  strip  off  a  thin  shred  from  a  bone  which  has  been 
decalcified  in  nitric  acid  and  afterwards  kept  for  some  time  in  dilute  alcohol. 
Mount  the  shred  in  water.  Observe  the  fibrous  structure  of  the  lamellae. 
Look  for  perforating  fibres  or  the  holes  from  which  they  have  been  dragged 
out.     Sketch  a  small  piece  of  the  thin  edge  of  a  lamella. 

3.  Stain  with  dilute  magenta  very  thin  sections  of  compact  bone  which 
has  been  decalcified  hi  chromic  or  picric  acid,  and  mount  in  dilute  glycerine, 
cementing  at  once.  Look  for  fibres  of  Sharpey  piercing  the  circumferential 
lamellae.  The  elastic  perforating  fibres  are  more  darkly  stained  than  the 
others.  Notice  the  stained  nuclei  of  the  bone-corpuscles  in  the  lacunae. 
In  the  thinnest  parts  of  the  sections  try  to  make  out  the  blood-vessels  and 
other  structures  in  the  Haversian  canals. 

4.  Mount  in  Canada  balsam  sections  of  marrow  (from  a  long  bone)  stained 
with  hematoxylin  or  borax-carmine.'  Observe  the  fat- cells,  the  reticular 
tissue  supporting  them,  the  proper  marrow-cells  in  this  tissue,  &c. 

5.  Tease  in  saline  solution  some  of  the  red  marrow  from  the  rib  of  a 
recently  killed  animal.  Observe  and  sketch  the  proper  marrow-cells  and 
look  for  myeloplaxes  and  nucleated  coloured  blood-corpuscles.  If  examined 
carefully,  amceboid  movements  may  be  detected  in  the  latter  and  in  the 
marrow-cells. 


Bone  is  a  connective  tissue  in  which  the  ground- substance  is  im- 
pregnated with  salts  of  lime,  chiefly  phosphate,  these  salts  constituting 
about  two-thirds  of  the  weight  of  the  bone.  When  bones  are  macerated 
this  earthy  matter  prevents  the  putrefaction  of  the  animal  matter. 
When  bones  are  calcined  they  lose  one-third  of  their  weight,  owing  to 
the  destruction  of  the  animal  matter  ;  when  steeped  in  acid  the  earthy 
salts  are  dissolved  and  only  the  animal  matter  is  left.  This,  like 
areolar  and  fibrous  tissue,  is  converted  into  gelatine  by  boiling. 

Bony  tissue  is  either  compact  or  cancellated.  Compact  bone  is 
dense  like  ivory  ;  cancellated  is  spongy  with  obvious  interstices.  The 
outer  layers  of  all  bones  are  compact,  and  the  inner  part  is  generally 
cancellated,  but  the  shaft  of  a  long  bone  is  almost  entirely  made  up  of 

1  See  Appendix. 


BONE 


49 


compact  substance  except'  along  the  centre,  which  is  hollow  and  filled 
with  marrow.  The  interstices  of  cancellated  bone  are  also  occupied 
by  marrow.  Externally  bones  are  covered  except  at  the  joints  by  a 
vascular  fibrous  membrane,  the  periosteum. 

True  bone  is  always  made  up  of  lamella,  and  these  again  are  com- 
posed of  fine  fibres  lying  in  a  calcified  ground-substance.  Between 
the  lamellae  are  branched  cells,  the  bone-corpuscles,  which  he  in  cell- 
spaces  or  lacuna.  The  ramified  passages  which  contain  the  cell-pro- 
cesses are  termed  canaliculi. 

In  cancellated  bone  the  blood-vessels  run  in  the  interstices  supported 
by  the  marrow.  In  compact  bone  they  are  contained  in  little  canals — 
the  Haversian  canals — which  everywhere  pervade  the  bone.  These 
canals  are  about  O05  mm.  i-J^  inch)  in  diameter,  but  some  are 
smaller,  others  larger  than  this.  Their  general  direction  is  longitudinal, 
i.e.  parallel  to  the  long  axis  of  the  bone,  but  they  are  constantly  united 
by  transversely  and  obliquely  running  passages.     In  a  section  across 


■^ 


IISJW 


Fig.  58. — Trassverse  se<  nos  op  a  bone  (ulna).    (Magnified  20  diameters.) 

The  openings  of  the  Haversian  canals  are  seen  encircled  by  concentric  lamella?.  Other  lamella? 
run  parallel  with  the  surface  l 

the  >haft  of  a  long  bone  they  are  seen  as  small  rounded  or  irregular 
holes  I  fig.  58  i.  When  the  section  has  been  made  by  grinding,  the 
holes  get  filled  up  with  air  and  debris,  and  they  then  look  black  by 


"X) 


THE   ESSENTIALS  OF  HISTOLOGY 


transmitted  light,  as  do  also  the  lacuna?  and  canaliculi  (fig.  59).  Most 
of  the  lamella?  in  compact  bone  are  disposed  concentrically  around  the 
Haversian  canals  ;  they  are  known  as  the  Haversian  lamellae,  and  with 


Fig.  59. — Transverse  section*  of  compact  tissue  (of  humerus).    (Magnified 
about  150  diameters.) 

Three  of  the  Haversian  canals  are  seen,  with  their  concentric  rings;  also  the  lacunae,  with 
the  canaliculi  exteuding  from  theru  across  the  direction  of  the  lauiellre.  The  Haversian 
apertures  had  become  filled  with  air  and  debris  in  grinding  down  the  section,  and  therefore 
appear  black  in  the  figure,  which  represents  the  object  as  viewed  with  transmitted  light. 

the  included  canal  form  what  is  known  as  a  Haversian  system.  The 
lacuna?  of  a  Haversian  system  communicate  with  one  another  and 
with  the  Haversian  canal,  but  not  as  a  rule  with  the  lacuna?  of  other 
Haversian  systems.  The  angular  interstices  between  the  Haversian 
systems  are  generally  occupied  by  bony  substance,  which  is  fibrous  but 
not  distinctly  lamellar.  Besides  the  lamellae  of  the  Haversian  systems 
there  is  a  certain  thickness  of  bone  at  the  surface,  immediately  under- 
neath the  periosteum,  which  is  composed  of  lamella?  arranged  parallel 
with  the  surface;  these  are  the  circumferential  ox  periosteal  lamcllce 
(fig.  58,  a).  They  are  pierced  here  and  there  by  canals  for  blood- 
vessels, which  are  proceeding  from  the  periosteum  to  join  the  system 
of  Haversian  canals,  and  also  by  calcified  bundles  of  white  fibres  and 
by  elastic  fibres  which  may  also  be  prolonged  from  the  periosteum. 
These  are  the  perforating  fibres  of  Sharp ey  (fig.  60). 

The  lamella?  of  bone  are  fibrous  in  structure.  This  may  be  seen  in 
shreds  torn  off  from  the  superficial  layers  of  a  decalcified  bone  (fig. 
61).  The  fibres  often  cross  one  another  in  adjacent  lamella?,  and  in 
the  Haversian  systems  they  run  in  some  lamella?  concentrically,  in 
others  parallel  with  the  Haversian  canal.  In  shreds  of  lamella?  which 
have  been  peeled  off  from  the  surface  the  perforating  fibres  may  some- 
times be  seen  projecting  from  the  surface  of  the  shred,  having  been 


BONE 


51 


Fig.  60. — Transverse  section  of  decalcified  human  tibia,  from  near  the 
surface  of  the  shaft. 

h,  ii.  Haversian  canals,  with  their  systen  brie  lamellae ;  in  all  the  rest  of  the  figure 

the  lamella;  are  circumferential;  s,  ordinary  perforating  fibres  of  Sharpey ;  e,  e,  elastic 

perforating  fibres.    Drawn  under  a  power  of  about  15u  diameters. 


^ 


Fig.  61. — Lamells  torn  off  from  a  decalcified  human  parietal  rune  at 

SOME    DEPTH    FROM    nil     -i  Ki  A(  I  . 

■(,  lamella1,  showing  decussating  fibres;  '>.  6,  thicker  part,  where  several  lamella;  are  super- 
posed; r.  c,  perforating  fibres:  the  fibrils  which  compose  them  are  not  shown  in  the 
figure.    Apertures  through  w  1 . i > •  1 »  perforating  fibres  had  passed  are  seen,  especially  in  the 
lower  part,  a,  a,  of  the  figure.    Magnitude  as  seen  under  a  power  of  800,  but  not  drawn  to 
scale. 


E  2 


52 


THE   ESSENTIALS   OF  HISTOLOGY 


torn  out  of  the  deeper  lamellae  (fig.  61  c,  c).  Where  tendons  or  liga- 
ments are  inserted  into  bone,  their  bundles  of  white  fibres  are  prolonged 
into  the  bone  as  perforating  fibres. 

The  lacuna?  are  occupied  by  nucleated  corpuscles,  which  send 
branches  along  the  canaliculi. 

The  Haversian  canals  contain  one  or  two  blood-capillaries  and 
nervous  filaments,  besides  a  little  connective  tissue ;  and  the  larger 
ones  may  also  contain  a  few  marrow-cells.  There  are  also  cleft-like 
lymphatic  spaces  running  parallel  with  the  vessels  and  connected  by 
means  of  canaliculi  with  neighbouring  lacunae  in  the  osseous  substance 
(fig.  62). 


Fig.  62. — Section  of  a  Haversian  canal,  showing  its  contents. 
(Highly  magnified.) 

a,  small  arterial  capillary  vessel ;  r,  large  venous  capillary :  n,  pale  nerve-fibres  cut  across ; 
/,  cleft-like  lymphatic  vessel  :  one  of  the  cells  forming  its  wall  communicates  by  fine 
branches  with  the  branches  of  a  bone-corpuscle.  The  substance  in  which  the  vessels 
run  is  connective  tissue  with  ramified  cells  ;  its  finely  granular  appearance  is  probably  due 
to  the  cross-section  of  fine  fibrils.    The  canal  is  surrounded  by  several  concentric  lamellae. 


The  periosteum,  which  is  best  studied  in  sections  from  a  bone  which 
has  been  decalcified  in  chromic  or  picric  acid,  is  a  fibrous  membrane 
composed  of  two  layers,  the  inner  of  which  contains  many  elastic 
fibres.  In  the  outer  layer  numerous  blood-vessels  ramify  and  send 
from  it  branches  to  the  Haversian  canals  of  the  bone.  The  periosteum 
ministers  to  the  nutrition  of  the  bone,  partly  on  account  of  the  blood- 
vessels it  contains,  partly,  especially  in  young  animals,  on  account  of 
the  existence  between  it  and  the  bone  of  a  layer  of  osteoblasts  or  bone- 
forming  cells,  a  remainder  of  those  which  originally  produced  the  bone. 

The  marrow  of  bone  is  of  a  yellow  colour  in  the  shafts  of  the  long 
bones,  and  is  there  largely  composed  of  adipose  tissue,  but  in  the  can- 
cellated tissue  it  is  red,  the  colour  being  partly  due  to  the  large  amount 
of  blood  in  its  vessels.  This  red  marrow  is  chiefly  composed  of  round 
nucleated  cells — the  marrow-cells  (fig.  63,  e-i) — which  resemble  large 
lymph-corpuscles,  and,  like  these,  are  amoeboid.  There  are  also  to  be 
seen  mingled  with  them  a  number  of  corpuscles  somewhat  smaller  in 
size,  but  nucleated  and  amoeboid,  and  of  a  reddish  tint  (fig.  63,  j-t); 
these  are  believed  to  be  cells  in  process  of  development  into  coloured 


MARROW 


53 


blood-corpuscles  (hcematoblasts).  Lastly  the  marrow  contains  a  certain 
number  of  very  large  cells  with  multiple  nuclei,  the  myeloplaxes  ifig. 
63,  a,  b,  c,  d).  These  are  especially  numerous  wherever  bone  is 
becoming  absorbed.  The  marrow  is  very  vascular,  the  capillaries  and 
veins  being  large  and  thin-walled ;  indeed,  according  to  some  authorities, 


©  %  <®  0  %  l  g 


Fig.  C3. — Cells  of  the  red  marrow  of  the  guinea-pig.    (Highly  magnified.) 

a,  a  large  cell,  the  nucleus  of  which  appears  to  be  partly  divided  into  three  by  constrict: 
6.  a  cell  the  enlarged  nucleus  of  -  an  appearance  of  being  constricted  into  a 

number  of  smaller  nuclei ;  c,  a  so-called  giant-cell  or  myeloplaxe  with  many  nuci._. 
smaller  myeloplaxe  with  three  nuclei :  e-i,  proper  cells  of  the  marrow  ;  j-t,  various  forms 
of  coloured  nucleated  cells,  some  in  process  of  division. 


the  walls  of  the  capillaries  are  imperfect,  so  that  there  is  an  open  com- 
munication between  them  and  the  interstices  of  the  tissue,  and  in  this 
way  it  is  supposed  that  the  coloured  blood-disks,  which  are  believed  to 
be  produced  from  the  coloured  nucleated  cells  of  the  marrow,  may  get 
into  the  circulation. 


54  THE   ESSENTIALS  OF  HISTOLOGY 


LESSON   XIV. 
DEVELOPMENT  OF  BONE. 

1.  Mount  in  Canada  balsam  a  section  of  the  lower  jaw  of  a  foetus  which  has 
been  stained  in  bulk  with  magenta  or  hematoxylin  and  embedded  in  paraffin.1 
Find  the  part  where  the  lower  jaw-bone  is  becoming  ossified,  and  carefully 
study  the  appearances  which  it  presents.  The  bone  is  prolonged  in  the  form 
of  osteogenic  fibres  which  are  covered  with  osteoblasts. 

2.  Intrarnembranous  ossification  may  also  be  studied  in  the  parietal  bone 
of  a  fcetus  which  has  been  preserved  in  Midler's  fluid.  Apiece  of  the  growing 
edge  is  scraped  free  from  its  investing  membranes  and  mounted  in  glycerine 
or  Farrant. 

3.  Moimt  in  Canada  balsam  sections  of  a  fcetal  limb  which  has  been  stained 
with  magenta.  The  bones  will  be  found  in  different  stages  of  ossification, 
those  of  the  digits  being  least  developed.  Make  sketches  illustrating  the 
three  chief  stages  of  endochondral  ossification.  Notice  the  peculiar  ter- 
minal ossification  of  the  third  phalanx. 

4.  Make  with  a  sharp  scalpel  a  longitudinal  section  at  the  line  of  ossifica- 
tion in  a  more  advanced  bone  which  has  not  been  decalcified.  These 
sections  will  show  the  mode  of  progress  of  the  calcification.  The  sections 
can  be  mounted  in  Farrant's  solution. 


True  bone  is  essentially  formed  in  all  cases  by  an  ossification  of 
connective  tissue.  Sometimes  the  bone  is  preceded  by  cartilage,  which 
first  of  all  becomes  calcined,  and  this  is  then  invaded,  and  for  the  most 
part  removed,  by  an  embryonic  tissue  which  re-deposits  bony  matter  in 
the  interior  of  the  cartilage,  whilst  at  the  same  time  layers  of  bone  are 
being  formed  outside  underneath  the  periosteum.  This  is  intracar- 
tilaginous  or  endochondral  ossification.  Sometimes  the  bone  is  not 
preceded  by  cartilage,  and  then  the  only  process  which  occurs  is  one 
corresponding  to  the  subperiosteal  ossification  of  the  former  variety  ; 
the  ossification  is  then  known  as  intrarnembranous. 

Ossification  in  Cartilage. — This  may  be  described  as  occurring  in 
three  stages.  In  the  first  stage  the  cells  in  the  middle  of  the  cartilage 
become  enlarged  and  arranged  in  rows  radiating  from  the  centre 
(fig.  64),  and  fine  granules  of  calcareous  matter  are  deposited  in  the 
matrix.      Simultaneously  with   this   the  osteoblasts  underneath   the 

1  For  the  methods  of  staining  and  embedding  1  and  3,  see  Appendix, '  Embedding 
in  Paraffin.' 


DEVELOPMENT   OF   BONE 


55 


periosteum  deposit  a  layer  or  layers  of  fibrous  lamella?  upon  the  surface 
of  the  cartilage,  and  these  lamelhe  also  become  calcified  (fig.  64,  im). 
As  they  are  formed  some  of  the  osteoblasts  (o)  are  included  between 
them  and  become  bone-corpuscles. 


Fig.  64. — Section  of  phalangeal  bone  of  human  foetus,  at  the  time  of 

commencing   ossification.     (Magnified  about  7.")  diameters.) 

The  cart  the  centre  an  irated  from  one  another  by  dark-looking 

I   matrix;    im,   layer  of  bone  deposited  underm  riostenm  ;  o,  layer  of 

by  which  this  layer  has  been  formed.    Some  of  the  osteoblasts  arc-  already  em- 
bedded in  the  new  bone  as  lacun®.   Tl  becoming  enlarged  and  ft 
and  arranged  in  row.-  above  and  below  the  calcified  centre.    At  the  ends  of  the  carti  age 
the  cells  are  small  and  the  groups  are  irregularly  arranged ;   the  fibrous  periosteum  is 
nut  sharply  marked  <>tV  from  the  cartilage. 


In  the  second  stage  some  of  the  subperiosteal  tissue  eats  its  way 
through  the  newly  formed  Layer  of  bone  and  into  the  centre  of  the  cal- 
cified cartilage  (fig.  65,  ir).  This  is  freely  absorbed  before  it,  so  thai 
large  spaces  are  produced  which  are  filled  with  osteoblasts  and  contain 


50 


THE   ESSENTIALS   OF   HISTOLOGY 


numerous  blood-vessels  which  have  grown  in  at  the  same  time.  The 
spaces  are  termed  medullary  spaces,  and  this  second  stage  may  be 
termed  the  stage  of  irruption. 


Fig.  G5. — Section  of  part  of 

ONE   OF   THE    LIMB-BONES  OF 

A  FCETAI.  CAT.  AT  A  HOKE 
ADVANCED  STAGE  OF  OSSIFI- 
CATION THAN  IS  iuimu:- 
SENTED      IX      FIG.      64,      AND 

SOMEWHAT  MORE  HIGHLY 
MAGNIFIED. 

The  calcification  of  the  cartilage- 
matrix  has  advanced  from  the 
centre,  and  is  extending  between 
the  groups  of  cartilage-cells 
which  are  arranged  in  character- 
istic rows.  The  subperiosteal 
bony  deposit  dm)  has  extended 
pari  passu  with  the  calcification 
of  the  cartilage-matrix.  The 
cartilage-cells  in  the  primary 
areola;  are  mostly  shrunken  and 
stellate  :  in  some  cases  they  have 
dropped  out  of  the  space.  At  ir 
and  in  two  other  places  an  irrup- 
tion of  the  subperiosteal  tissue, 
composed  of  ramified  cells  with 
osteoblasts  and  growing  blood- 
vessels, has  penetrated  the  sub- 
periosteal bony  crust,  and  has 
begun  to  excavate  the  secondary 
areolae  or  medullary  spaces  ;  p, 
fibrous  layer  of  the  periosteum  ; 
o,  layer  of  osteoblasts,  some  of 
them  are  embedded  in  the  osseous 
layer  as  h.me-corpuscles  in  la. 
cunse  :  6/,  blood-vessels  occupied 
by  blood-corpuscles.  Beyond  the 
line  of  ossific  advance  the  perios- 
teum may  be  noticed  to  be  dis- 
tinctly incurved.  This  incurva- 
tion is  gradually  moved  on.  the 
cartilage  expanding  behind  it 
until  the  head  of  the  hone  is 
reached,  when  it  forms  the  peri- 
osteal notch  or  groove  represented 
in  fig.  66,  p.  57. 


In  the  tliird  stage  of  endochondral  ossification  there  is  a  gradual 
advance  of  the  ossification  towards  the  extremities  of  the  cartilage, 
and  at  the  same  time  a  gradual  deposition  of  fresh  bony  lamella3  and 
spicules  on  the  walls  of  the  medullary  spaces,  and  on  the  surface  of 
the  new  bone  under  the  periosteum.  The  advance  into  the  cartilage 
always  takes  place  by  a  repetition  of  the  same  changes,  the  cartilage- 
cells  first  enlarging  and  becoming  arranged  in  rows,  the  matrix 
between  the  rows  becoming  calcified,  and  then  the  calcified  cartilage 
becoming  excavated  from  behind  by  the  osteoblastic  tissue  so  as  to  form 
new  medullar}-  spaces  (fig.  67).     The  walls  of  these  are  at  first  formed 


DEVELOPMENT   OF   BONE 


57 


only  by  remains  of  the  calcified  cartilage-matrix  (fig.  67,  c),  but  they 
soon  become  thickened  by  lamella   of  fibrous  bone    I  b)   which   are 


Fig.  66. — Longitudinal  sec- 
tion THROUGH  THE  UPPER 
HALF    OF     THE    DECALCIFIED 

HUMERUS  <  >F  A  KKTAL  SHEEP, 
AS  SEEN  UNDER  A  MAGNIFY- 
ING POWER  OF  ABOUT  30 
DIAMETERS. 

ic,  the  part  of  the  shaft  which  was 
primarily  ossified  in  cartilage ; 
what  remains  of  the  primary 
bone  is  represented  a-  dark,  en- 
veloped by  the  clear  secondary 
deposit.  The  areola  of  the  bone 
are  occupied  by  embryonic  mar- 
row with  osteoblasts,  and  blood- 
vessels variously  cut,  represented 
a-  dark  lines.  One  long  straight 
vessel 

the  line  of  ossification  far  into 
the  cartilaginous  head,  most  of 
the  others  loop  round  close  to  the 
cartilage.  At  one  or  two  places 
in  the  older  parts  of  the  bone 
elongated  groups  of  cartilage- 
cells  (c)  may  .-till  be  seen,  which 
have  escaped  absorption,  im.  the 
part  of  the  bone  that  has  been 
ossified  in  membrane,  that  is  to 
say.  in  the  osteoblastic  tissue 
under  the  periosteum.  It  is  well 
marked  off  from  the  central  por- 
tion, and  is  bounded,  peripherally, 
by  a  jagf  e  projections 

of  which  are  indistinctly  seen  to 
be  pro  aches  of  osteo- 

genic fibre-.   A  row  of  osl 

•  the  superficial  layer  of  the 
bone.    The  subperiosteal  layer  is 
prolong'-.]  above  into  the  thicken- 
ing I/O,  which  encroacl 
the  earl  ad  of  the 

bone,  and  in  which  are  seen, 
amongst  numerous  osteoblasts 
and  a  few  blood-vessels,  the 
straight  longitudinal  osteogenic 
fibres  (of),  ind  some  other  fibres 
crossing  them,  and  perhaps 
representing  fibres  of  sharper. 
The  calcareous  salts  havu  - 
removed  by  an  acid,  the  granular 
deposit  passing  up  between 
the  rows  of  cartilage-cells  is  not 
seen  in  this  specimen;  it  would 
have  extended  as  far  a-  a  line 
joining  the  marks  x  x.   Observe 

the  general   tendency  of   | 

ous  trabecule  and  the  vascular 

channels  between  them  to  radiate 
from  the  original  centre  of  ossifi- 
cation.   Thi-  is  found  to  prevail 
more  or  less  in  all  bom  ■ 
they  are  first  formed,  i 
the  direction    of    the  trabecular 
may  afterwards  become  modified 
in  relation  with  varying  physio- 
logical conditions,  and  es| 
a-  the  result  of  pressure  iu  dif- 
ferent directions. 


- 


deposited   by   the    osteoblasts,   and  between   which   bone-corpuscles 
become  included,  as  in  the  case  of  the  subperiosteal  bone.     The  latter 


58 


THE   ESSENTIALS   OF   HISTOLOGY 


advances  pari  passu  with  the  endochondral  calcification,  but  beyond 
this  the  uncalcified  cartilage  grows  both  in  length  and  breadth,  so  that 
the  ossification  is  always  advancing  into  larger  and  larger  portions  of 
cartilage  ;  hence  the  endochondral  bone  as  it  forms  assumes  the  shape 
of  an  hour-glass,  the  cylindrical  shape  of  the  whole  bone  being  main- 
tained by  additions  of  periosteal  bone  to  the  outside  (see  fig.  60).     The 


Fig.  67. — Part   of   a    loxgi- 
xrnixAi.    section    of     the 

DEVELOPING    FEMUR   OF  THE 

rabbit.  (Drawn  under  a 
magnifying  power  of  350 
diameters.) 

a,  rows  of  flattened  cartilage-cells  ; 
6,  greatly  enlarged  cartilage- 
close  to  the  advancing  bone, 
the  matrix  between  is  parti; 
calcified;  c,  d,  already  formed 
the  osseous  trabecule 
being  covered  with  osteoblasts 
( i  i.  except  here  and  there, 
win-re  an  osteoclast  (/> 
eroding  parts  of  the  tral 
</.  h  cartilage-cells  which  have 
become  shrunken  and  irregular 
in  shape.  From  the  mid 
the  figure  downwards  the  dark 
trabeculae,  which  are  forme. 1  of 
calcified  cartilage-matrix,  are  be- 
coming covered  with  secondary 
osseous  substance  deposited  by 
the  osteoblasts.  The  \ 
loops  at  the  extreme  limit  of  the 
bone  are  well  shown,  as  well  as 
the  abrupt  disappearance  of  the 
cartilage-cells. 


absorption  of  the  calcified  cartilage-matrix  appears  to  be  effected,  as  is 
the  case  with  absorption  of  bony  matter  wherever  it  occurs,  by  large 
multinucleated  cells  (fig.  67,/,/)  which  are  termed  osteoclasts.  They 
are  the  same  as  the  myeloplaxes  of  the  marrow. 

The  bone  which  is  first  formed  is  more  reticular  and  less  regularly 
lamellar  than  that  of  the  adult,  and  contains  no  Haversian  systems. 
The  regular  lamellae  are  not  deposited  until  some  little  time  after  birth, 
and  their  deposition  is  generally  preceded  by  a  considerable  amount  of 
absorption.  It  is  about  this  time  also  that  the  medullary  canal  of  the 
long  bones  is  formed  by  the  absorption  of  the  bony  tissue  which 
originally  occupies  the  centre  of  the  shaft. 


DEVELOPMENT   OF   BONE 


59 


After  a  time  the  cartilage  in  one  or  both  ends  of  the  long  bones  begins 
to  ossify  independently,  and  the  epiphyses  are  formed.  These  are  not 
joined  to  the  shaft  until  the  growth  of  the  bone  is  completed.  Growth 
takes  place  in  length  by  an  expansion  of  the  cartilage  i  intermediate  car- 
tilage) which  intervenes  between  the  shaft  and  the  epiphyses,  and  by  the 
gradual  extension  of  the  ossification  into  it ;  in  width  entirely  by  the 
deposition  of  fresh  bony  layers  under  the  periosteum.  In  the  terminal 
phalanges  of  the  digits  the  ossification  starts,  not  from  the  middle  of 
the  cartilage,  but  from  its  distal  extremity. 

For  the  regeneration  of  portions  of  bone  which  have  been  removed 
by  disease  or  operation  it  is  essential  that  the  periosteum  be  left. 


Fio.  68. — Part  of  the  growing  edge  of  the  developing  parietal  bone 

OF   A    FCETAL    CAT,    1^    IM  II    LONG. 

tp,  hcniv  spicules,  with  some  of  the  osteoblasts  embedded  La  them,  producing  the  lacuna-:  of, 
igenic  fibres  prolonging  the  spicules,  with  osteoblasts  (osl)  between  them  and  applied 
to  them. 


Intramembranous  ossification.  In  this  variety  of  ossification,  the 
bone  is  not  preceded  by  cartilage  at  all,  and  therefore  no  endochon- 
dral bone  is  formed,  but  the  calcification  occurs  in  a  sort  of  embryonic 
fibrous  tissue  which  contains  numerous  osteoblasts  and  blood-vessels 
(fig.  68).  The  fibres  of  this  tissue  (osteogenic  fibres),  which,  like  those 
of  fibrous  tissue,  are  collected  into  small  bundles,  become  enclosed  in 
a  calcareous  matrix  ;  and  as  the  fibres  grow,  the  calcification  extends 
further  and  further,  so  that  bony  spicules  ore  formed,  which,  as  they 
become  thickened,  run  together  to  form  reticular  layers, leaving  spaces 
filled   with   osteoblasts    around    the    blood-vessels.      The   osteogenic 


GO  •  THE  ESSENTIALS  OF   HISTOLOGY 

fibres  are  covered  with  osteoblasts,  and  as  the  bone  forms,  some  of 
these  become  left  as  bone-corpuscles  -within  lacuna?.  Thus  in  every 
particular  the  development  of  these  bones  resembles  that  of  the  sub- 
periosteal layer  of  endochondral  bone,  which  is  also  to  be  considered 
as  an  instance  of  intramembranous  ossification,  although  taking  place 
on  the  surface  of  cartilage.  Moreover,  it  is  the  same  subperiosteal 
tissue  which  deposits  the  true  or  secondary  bone  upon  those  parts 
of  the  calcified  cartilage-matrix  which  have  escaped  absorption ;  and 
this  must  also,  therefore,  be  reckoned  as  developed  according  to  the 
same  type.  In  fact,  even  in  intracartilaginous  ossification,  very  little 
of  the  calcified  cartilage-matrix  eventually  remains  ;  this  being  almost 
wholly  replaced  by  true  or  fibrous  bone  which  has  been  formed  by 
osteoblasts. 


61 


LESSONS   XT.   and   XVI. 

STRUCTURE   OF  MUSCLE. 

LESSON   XV. 

1.  Take  a  shred  of  muscle  from  a  recently  killed  mammal,  and  on  a  dry  slide 
carefully  separate  Ions  pieces  of  muscidar  fibre  (single  fibres  if  possible)  and 
stretch  them  out,  keeping  them  moist  during  the  process  by  breathing  on  the 
slide.  Put  a  drop  of  seruui  on  the  cover-glass  before  placing  this  over  the 
preparation.  Study  first  with  a  low,  then  with  a  high  power.  Sketch  all  the 
appearances  to  be  seen  in  a  small  piece  of  a  fibre,  focussing  carefully  the  most 
superficial  layers.  Notice  the  oval  nuclei  immediately  under  the  sarcolernma. 
Then  allow  a  little  dilute  acetic  acid  to  run  under  the  cover-glass  and  watch 
its  effect. 

2.  Prepare  some  fibres  of  frog's  muscle  in  the  same  way,  but  mount  in 
salt  solution  instead  of  serum.  Notice  the  muscular  substance  shrinking 
away  here  and  there  from  the  sarcolernma,  which  then  becomes  distinctly 
visible.  Sketch  a  piece  of  sarcolernma  bridging  across  an  interval  thus  pro- 
duced. 

8.  Mount  in  Fan-ant  transverse  sections  of  fresh  muscle  which  have  been 
cut  whilst  frozen,  and  at  once  placed  in  1  per  cent,  nitrate  of  silver  solution. 
Take  care  to  prevent  the  cover-glass  from  pressing  on  the  sections.  Examine 
first  with  a  low  and  then  with  a  high  power.  Sketch  the  appearances  which 
are  seen. 

In  each  of  the  above  preparations  measure  the  diameter  of  some  of  the 
fibres. 


LESSON   XVI. 


1.  Cut  off  the  head  of  a  water-beetle  and  bisect  the  trunk  with  scissors  so  as 
to  expose  the  interior.  Notice  two  kinds  of  muscidar  tissue,  the  one  belonging 
to  the  legs  greyish  in  colour,  the  other  attached  to  the  wings  yellowish. 
Preparations  i  if  both  kinds  ofmuscle  are  to  be  made  in  the  same  way  as  living 
mammalian  muscle  (see  previous  Lesson),  but  they  are  to  be  mounted  either 
without  the  addition  of  any  thud  or  in  a  drop  of  the  insect's  blood.  In  both 
preparations  the  dark-looking  air-tubes  or  tracheae  form  prominent  objects 
ramifying  amongst  the  fibres.  Observe  the  structure  of  the  two  kinds  of 
muscle,  noting  especially  the  fine  fibrils  of  the  wing  muscles  and  the  muscle- 
rods  in  the  large  fibres  of  the  leg  muscles.  If  the  preparation  is  made  quickly, 
waves  of  contraction  will  probably  be  observed  passing  along  the  last-named 
fibres. 

The  remainder  of  the  water-beetle  may  bo  put  into  spirit  (pinned  upon  a 
cork  so  that  the  muscles  are  well  stretched)  and  preparations  made  on  a 
future  day  after  the  manner  described  in  the  next  preparation. 

2.  Place  in  logwood  a  small  shred  of  mammalian  muscular  tissue  which 
has  been  stretched  upon  a  cork  and  hardened  in  alcohol.     "When  it  is  deeply 


6i> 


THE    ESSENTIALS   OF   HISTOLOGY 


stained,  wash  it  in  water  and  with  needles  break  the  fibres  up  in  Farrant's 
solution  into  as  fine  fibrils  as  possible.  Cover  and  examine  with  a  high 
power. 

3.  Tear  off  a  small  shred  of  the  muscular  coat  of  a  piece  of  intestine  which 
has  been  from  -J4  to  48  hours  in  (£  per  cent.)  bichromate  of  potash  solution. 
Hold  the  shred  with  forceps  in  a  drop  of  water  and  fray  it  out  with  a  needle. 
In  this  process  many  cells  will  be  set  free  and  can  be  seen  with  a  low  power. 
The  preparation  may  then  be  covered  and  examined  with  a  high  power. 
Sketch  one  of  the  cells.  Then  allow  dilute  logwood  to  pass  under  the  cover- 
glass  and  lastly  a  drop  of  glycerine.  Sketch  another  cell  after  staining. 
Measure  two  or  three  cells  and  their  nuclei. 


Voluntary  muscle  is  composed  of  long  cylindrical  fibres,  measuring 
on  an  average  about  3-^  inch  in  diameter  in  mammalian  muscles,  but 
having  a  length  of  an  inch  or  more.  Each  fibre  has  an  elastic  sheath, 
the  sarcoiemma,  which  encloses  the  contractile  substance.  The  sarco- 
lemma  is  seldom  distinct,  unless  the  contained  substance  becomes 
broken  (fig.  69). 


Fig.  69. — Sarcolemma 

of  mammalian  mus- 
cle, highly  magni- 
FIED. 

The  fibre  is  represented  at 
a  place  where  the  mus- 
cular substance  has  be- 
come ruptured  ami  lias 
shrunk  away,  leaving  the 
sarcoiemma  (with  a 
nucleus  adhering  to  it) 
clear.  The  fibre  had  been 
treated  with  serum  acidu- 
lated  with  acetic  acid. 


Fig.   70.  —  Muscular 

FIBRE  i>F  A  MAMMAL 
EXAMINED  FRESH  IN 
SERUM,  HIGHLY  MAG- 
NIFIED. THE  SURFACE 
OF  THE  FIBRE  BEING 
ACCURATELY  FO- 

CUSSED. 

The  nuclei  are  seen  on  the 
flat  at  the  surface  of  the 
fibre,  and  iu  profile  at 
the  edges. 


The  contractile  substance  of  the  fibre  is  characterised  by  the  alter- 
nate dark  and  light  stripes  which  run  across  the  length  of  the  fibre  ; 
hence  the  name,  cross-striated  or  striped  muscle.     On  focussing,  it 


STRUCTURE   OF   MUSCLE 


63 


can  be  seen  that  the  stripes  pass  through  the  whole  thickness  of  the 
fibre  ;  they  may  therefore  be  looked  upon  as  representing  alternate 
disks  of  dark  and  light  substance.  If  the  surface  be  very  carefully 
focussed,  double  rows  of  granules  are  seen  lying  in  or  at  the  bounda- 
ries of  the  light  streaks,  and  very  fine  longitudinal  lines  may,  with  a 
good  microscope,  be  detected  running  through  the  dark  streak,  and 
uniting  the  minute  granules  (fig.  70 1.  These  fine  lines,  with  their 
enlarged  extremities  the  granules,  are  known  as  muscle-rods  ;  they  are 
more  conspicuous  in  the  muscles  of  insects. 


-is 
-an- 
-z's 


Fig.  72. —  Diagramma- 
tic REPRESENTATION 
OF     A      MUSCLE-*  ASE. 

en,  muscle-prism,   i 
ingof  a  bundle  of  muscle- 
rods  :  it,  fluid  substance. 


Fin    71. — Portion  of  a  medium- 

BIZED  HUMAN  MUSCULAR  FIBRE, 
SHOWING  THE  INTERMEDIATE 
LINE    MENTIONED    IN    THE    TEXT. 


If  instead  of  focussing  the  surface  of  the  fibre  it  be  observed  in  its  depth. 
a  different  appearance  is  frequently  visible,  namely  a  line  dotted  line  bisecting 
each  clear  stripe  (tig.  71)  :  but  this  appearance  is  probably  due  to  an  optical 
effect  caused  by  the  light  being  transmitted  between  disks  of  different 
refrangibility. 

The  fine  line  bisecting  the  clear  stripe  is.  however,  taken  by  many  histolo- 
giflte  to  represent  a  definite  structure,  and  is  often  known  as  Krause's  mem- 
brane, having  l>een  described  by  Krause  as  connected  with  the  sarcolemma  and 
dividing  the  muscle-fibre  into  so  many  flat  compartments.  Krause  further  de- 
scribed these  compartments  as  divided  longitudinally  by  fine  membranes,  so 
that  tlie  muscle-substance  may,  according  to  hirn.be  regarded  as  co 
little  cylindrical  '  cases  '  (fig.  72)  each  containing  in  the  centre  a  portion  of  the 
dark  disk,  and.  above  and  below  this,  portions  of  the  light  disks  (which  are 
fluid  according  to  this  author).1 

1  For  other  views  repanlinpr  the  structure  of  striated  muscular  fibre,  the  student 
is  referred  to  Quain's  Anatomy,  9th  edition,  vol.  ii.  pp.  127  to  129. 


C4 


THE   ESSENTIALS   OF  HISTOLOGY 


Besides  the  sarcolernma  and  striated  substance,  a  muscular  fibre  also 
exhibits  a  number  of  oval  nuclei  which  have  the  usual  reticular  structure 
of  cell-nuclei.  Sometimes  there  is  a  little  granular  substance  (proto- 
plasm) at  each  pole  of  the  nucleus.  In  mammalian  muscle  the  nuclei 
lie  immediately  under  the  sarcolernma  (figs.  69,  70),  except  in  certain 
fibres,  e.g.  those  which  compose  the  red  muscles  of  some  animals,  such 
as  the  hare  and  rabbit,  and  which  occur  scattered  amongst  the  ordinary 
fibres  in  mammalia  generally.  In  these  the  nuclei  are  distributed 
through  the  thickness  of  the  fibre,  and  this  is  also  the  case  in  all  the 
muscular  fibres  of  the  frog. 

The  transverse  section  of  a  muscle  shows  the  fibres  to  be  nearly 
cylindrical  in  figure.  Between  the  fibres  there  is  a  certain  amount  of 
areolar  tissue,  which  serves  to  support  the  blood-vessels  and  also  unites 
them  mto  fasciculi ;  the  fasciculi  are  again  united  together  by  a  larger 
amount  of  this  intramuscular  connective  tissue. 

On  examining  the  transverse  section  of  a  fibre  with  a  high  power, 
it  is  seen  to  be  subdivided  everywhere  into  small  angular  fields,  the 
areas  of  Cohnheim.  These  probably  represent  sections  of  tbe  longi- 
tudinal fibrils  into  which  a  muscular  fibre  splits  after  death,  or  after 
being  hardened  in  certain  reagents,  e.g.  alcohol,  chromic  acid,  or  osrnic 
acid. 


Fig.  73. — Section  of  a  muscular  fibre 
showing  areas  of  coiinheim. 


Fig.  74. — Living  muscle  of  -water- 
beetle     (dytiscis     marginalia). 

(Highly  magnified.) 

s,  sarcolernma ;  a,  dim  stripe ;  b,  bright 
stripe;  c,  row  of  dots  in  bright  stripe, 
which  seem  to  be  the  enlarged  ends  of 
rod-shaped  particles,  d. 

In  the  muscles  of  insects  the  stripes  are  relatively  broad,  and  their 
structure  can  be  more  readily  seen  than  in  mammals.  In  the  living 
fibres  from  the  muscles  of  tbe  legs,  the  appearance  of  fine  longitudinal 
lines  traversing  the  dark  stripes,  and  terminating  within  the  light 
stripes  in  rows  of  dots,  is  very  obvious.  When  the  fibres  contract,  the 
light  stripes  are  seen,  as  the  fibre  shortens  and  thickens,  to  become 


STRUCTURE   OF  MUSCLE 


65 


dark,  an  apparent  reversal  being  thereby  produced  in  the  striaB.  This 
reversal  is  due  to  the  enlargement  of  the  rows  of  dark  dots,  and  the 
formation  by  their  juxtaposition  and  blending  of  dark  disks,  whilst  the 
muscular  substance  between  these  disks  has  by  contrast  a  bright 
appearance. 

The  wing-muscles  of  insects  are  easily  broken  up  into  very  fine 
fibres  or  fibrils,  which  also  show  alternate  dark  and  light  stria?.  The 
number  and  relative  thickness  of  these  differ,  however,  considerably, 
according  to  the  amount  of  stretching  of  the  fibres  (fig.  75).  Muscle- 
rods  are  not  seen  in  these  fibres. 


e 

>  _ 

e 

t 

t 


e 
e 
e 


m 
■  be 
m 
,5c 
m 


Fig.  75. — Fibres  of  the  wixg-musci.es  of  an  insect. 

The  fibres  are  in  different  conditions  of  extension,  from  A  least  extended,  to  D  most  ex- 
tended, e,  e,  chief  substance  of  the  fibre  ;  m,  m,  intermediate  lines  or  disks ;  the  light 
bands,  be,  on  either  side  of  these  only  come  to  yiew  when  the  fibre  is  sufficiently  stretched 
(C)  ;  with  further  extension  (D),  the  middle  of  the  dark  band  appears  lighter,  fi.~ 

In  muscular  tissue  which  has  been  hardened  in  alcohol  and  certain 
other  reagents,  the  structural  appearances  are  a  good  deal  altered  from 
those  of  the  living  muscle,  although  the  cross-striae  are  still  very  obvious. 
There  is  also  a  considerable  tendency  for  the  fibres  to  split  up  longi- 
tudinally into  fibrils,  and  by  some  authorities  the  finest  of  such  fibrils 
are  regarded  as  the  ultimate  elements  of  the  fibre.  Certain  other 
reagents,  such  as  dilute  hydrochloric  acid,  cause  a  transverse  splitting 
of  the  fibres  into  disks,  and  these  effects  of  reagents  led  Bowman  to  form 
the  opinion  that  the  muscular  substance  may  be  in  reality  composed  of 
minute  prismatic  particles  set  side  by  side  in  rows  or  planes  to  form 
the  disks,  and  adhering  end  to  end  longitudinally  to  form  the  fibrils. 
To  these  constituent  particles  of  the  muscular  substance  he  gave  the 
name  of  '  sarcous  elements.' 

When  living  muscular  fibres  are  examined  by  polarised  light,  the 
whole  of  the  muscular  substance  except  the  muscle-rods  is  seen  to  be 
doubly  refracting,  looking  bright  in  the  dark  field  produced  by  crossing 
the  axes  of  the  Nichol's  prisms.  Contracted  muscle  and  dead  muscle 
show,  however,  alternate  bands  of  dark  and  light  under  those  circum- 
stances. 

Ending  of  muscle  in  tendon. — A  small  tendon-bundle  passes  to 


66 


THE   ESSENTIALS   OF  HISTOLOGY 


each  muscular  fibre  and  becomes  firmly  united  with  the  sarcolemma, 
which  extends  over  the  end  of  the  fibre  (fig.  76).  Further,  the  areolar 
tissue  between  the  tendon -bundles  is  continuous  with  that  which  lies 
between  the  muscular  fibres,  so  that  the  connection  of  a  muscle  to  its 
tendon  is  very  firm. 


p  — 


— s 


Fig.  76. — Termination  of  a  mus- 
cular  fibre  ix  tendon. 

m,  sarcolemma  ;  s,  the  same  membrane 
passing  over  the  end  of  the  fibre;  p, 
extremity  of  muscular  substance,  c, 
retracted  from  the  lower  end  of  the 
.-areolemma-tube;  /,  tendon-bundle 
passing  to  be  fixed  to  the  sarcolemma. 


Fig.  77. — Capillary  vessels  of 
muscle. 


Blood-vessels  of  muscle. — The  capillaries  of  the  muscular  tissue  are 
very  numerous.  They  run,  for  the  most  part,  longitudinally,  with 
transverse  branches,  so  as  to  form  long  oblong  meshes  (fig.  77).  In 
the  red  muscles  of  the  rabbit  and  hare,  the  transverse  capillaries  have 
small  dilatations  upon  them.  No  blood-vessels  ever  penetrate  the 
sarcolemma. 

Lymphatic  vessels,  although  present  in  the  connective-tissue  sheath 
(perimysium)  of  a  muscle,  do  not  penetrate  between  its  component 
fibres. 

The  nerves  of  voluntary  muscles  pierce  the  sarcolemma  and  ter- 
minate in  a  ramified  expansion  known  as  an  end-plate  (see  Lesson 
XIX.). 


STRUCTURE   OF  MUSCLE 


67 


Voluntary  muscular  fibres  are  developed  from  embryonic  cells  of 
the  mesoderm,  which  become  elongated,  and  the  nuclei  of  which  become 
multiplied,  so  as  to  produce  long  multi-nucleated  fusiform  or  cylindrical 
fibres.  These  become  cross-striated  at  first  along  one  side,  the  change 
gradually  extending  around  the  fibre  and  also  towards  the  centre  ; 
but  the  middle  of  the  fibre,  to  which  the  nuclei  are  at  first  confined, 
remains  for  some  time  unaltered  (fig,  78 1.  Eventually  the  change  in 
structure  extends  to  this  also,  and  the  nuclei  pass  gradually  to  occupy 
their  ordinary  position  under  the  sarcolemma,  which  by  this  time  has 
become  formed. 


Fig.  78. — Developing 
miscular  fibre, 
from     fcetus    of    2 

MONTHS. 
p,  central  protoplasm  with 
several  nuclei,  n,  scat- 
tered in  it ;  s,  commen- 
cing sarcolemma,  with 
striated  muscular  sub- 
stance developing  im- 
mediately beneath  it. 


Fig.  79.— Mttsculab  fibre-cells  from  the  mttscu- 
lab  coat  of"  the  small  intestine,  highly  mag- 
NIFIED. 

A.  A  complete  cell,  showing  the  nucleus  with  intra-nuclear 
network,  and  the  longitudinal  fibrillation  of  the  cell-sub- 
stance, with  finely  vacuolated  protoplasm  between  the  fibrils. 
B.  A  cell  broken  in  the  process  of  isolation  ;  the  delicate 
enveloping  membrane  projects  at  the  broken  end  a  little 
beyond  the  substance  of  the  cell. 


Involuntary  or  plain  muscular  tissue  is  composed  of  long,  some- 
what flattened,  fusiform  cells  (fig.  79),  which  vary  much  in  length,  but 
are  usually  not  more  than  -^  inch  long.     Each  cell  has  an  oval  or 

F  2 


68  THE  ESSENTIALS  OF  HISTOLOGY 

rod-shaped  nucleus,  which  shows  the  usual  intra-nuclear  network  and 
commonly  one  or  two  nucleoli.  The  cell -substance  is  longitudinally 
striated,  but  does  not  exhibit  cross-striae  like  those  of  voluntary  muscle. 
There  appears  to  be  a  delicate  sheath  to  each  cell.  There  is  a  little 
intercellular  cementing  substance  uniting  the  cells  together,  and  which 
can  be  stained  by  nitrate  of  silver.  The  fibres  are  collected  into  fas- 
ciculi. 

Plain  muscular  tissue  is  found  chiefly  in  the  walls  of  hollow  viscera ; 
thus  it  forms  the  muscular  coat  of  the  whole  of  the  alimentary  canal 
below  the  oesophagus,  and  occurs  abundantly  in  the  rnuscular  coat  of 
that  tube  also,  although  it  is  here  intermixed  with  cross-striated 
muscle ;  it  is  found  also  in  the  mucous  membrane  of  the  alimentary 
canal ;  in  the  trachea  and  its  ramifications ;  in  the  urinary  bladder 
and  ureters ;  in  the  uterus,  Fallopian  tubes,  and  ovary ;  in  the  pro- 
state, the  spleen,  and  muscle  of  Midler  in  the  orbit,  and  in  the  ciliary 
muscle,  and  iris.  The  walls  of  gland-ducts  also  contain  it,  and  the 
middle  coat  of  the  arteries,  veins,  and  lymphatics  is  largely  composed 
of  this  tissue.  It  occurs  also  in  the  skin,  both  in  the  secreting  part  of 
the  sweat-glands,  and  in  small  bundles  attached  to  the  hair-follicles  ; 
in  the  scrotum  it  is  found  abundantly  in  the  subcutaneous  tissue 
idartos). 

The  muscular  tissue  of  the  heart  constitutes  a  special  variety  of 
involuntary  muscular  tissue  (cardiac),  and  will  be  described  along  with 
that  organ. 


69 


LESSON   XVII. 

STRUCTURE   OF  NERVE-FIBRES. 

1.  Tease  a  piece  of  fresh  nerve  in  saline  solution,  injuring  the  fibres  as  little 
and  obtaining  them  as  long  and  straight  as  possible.  Study  the  rnedullated 
fibres,  carefully  noticing  all  the  structures  that  are  visible — viz.,  nodes  of 
Eanvier,  nuclei  of  primitive  sheath,  double  contour  of  medullary  sheath, 
medullary  segments,  &c.  Measure  the  diameter  of  half  a  dozen  fibres.  Draw 
a  short  length  of  a  fibre  very  exactly. 

2.  Prepare  a  piece  of  the  sympathetic  nerve  in  the  same  way.  Measure 
and  sketch  as  before. 

3.  Separate  (in  dilute  glycerine  or  Farrant)  into  its  fibres  a  small  piece  of 
nerve  that  has  been  twenty-four  hours  in  ^  per  cent,  osmic  acid.  The  nerve 
should  have  been  moderately  stretched  on  a  piece  of  cork  by  means  of  pins 
before  being  placed  in  the  acid.  Keep  the  fibres  as  straight  as  possible  and 
only  touch  them  near  their  ends  with  the  needles.  Sketch  two  portions  of  a 
fibre  under  a  high  power,  one  showing  a  node  of  Eanvier  and  the  other  a 
nucleus  of  the  primitive  sheath.  Look  for  fibres  of  Eeruak.  Measure  the 
length  of  the  nerve -segments  between  the  nodes  of  Eanvier. 

4.  Mount  in  Canada  balsam  sections  of  a  nerve  which  has  been  hardened 
in  picric  acid  and  stained  with  picro- carmine.  The  nerve  should  have  been 
stretched  out  before  being  placed  hi  the  hardening  solution.  Examine  the 
sections  first  with  a  low  and  afterwards  with  a  high  power.  Notice  the 
lamellar  structure  of  the  perineurium,  the  varying  size  of  the  nerve-fibres, 
the  axis  cylinder  in  the  centre  of  each  fibre,  &c.  Measure  the  diameter  of 
five  or  six  fibres,  and  sketch  a  small  portion  of  one  of  the  sections. 


Nerve-fibres  are  of  two  kinds,  rnedullated  and  non-medullated.  The 
cerebro- spinal  nerves  and  the  white  matter  of  the  nerve-centres  are 
composed  of  rnedullated  fibres ;  the  sympathetic  and  its  branches  is 
chiefly  made  up  of  non-medullated. 

The  rnedullated  or  white  fibres  are  characterised,  as  their  name 
implies,  by  the  presence  of  the  so-called  medullary  sheath  or  white 
substance.  This  is  a  layer  of  soft  substance,  chiefly  of  a  fatty  nature, 
which  encircles  the  essential  part  of  a  nerve-fibre,  viz.  the  axis-cylinder. 
Outside  the  medullary  sheath  is  a  delicate  but  tough  homogeneous 
membrane,  the  primitive  sheath  or  nucleated  sheath  of  Schwann,  but 


70 


TPIE   ESSENTIALS   OF  HISTOLOGY 


this  is  not  present  in  all  niedullated  fibres,  being  absent  in  tnose  which 
are  within  the  nerve-centres. 

The  medullary  sheath  is  composed  of  a  highly  refracting  fatty 


Fig.  80. — White  or  medullated 
nerve  -  fibres,  showing  the 
sinuous  outline  and  double 
contours. 


Fig.  81. — Portions  of  two  nerve-fibres 
stained  with  osmh  acid  (from  a 
young  rabbit).     (425  diameters.) 

R,  R.  Nodes  of  Ranvier,  with  axis-cylinder 
pa-sing  through,  a,  primitive  sheath  of 
the  nerve,  e,  opposite  the  middle  of  the 
segment,  indicates  the  nucleus  and  proto- 
plasm lying  between  the  primitive  sheath 
and  the  medullary  sheath.  In  A  the  nodes 
are  wider,  and  the  intersegmental  substance 
more  apparent  than  in  B. 


material,  which  gives  a  characteristic  dark  contour  and  tubular  appear- 
ance to  the  nerve-fibres.  It  affords  a  continuous  investment  to  the 
axis-cylinder,  except  that  it  is  interrupted  at  regular  intervals  in  the 


STRUCTURE 


OF 


Fig.  82. — A  -mall  part  of  a  medul- 

LATED    FIBRE.    HIGHLY    MAGNIFIED. 

The  fibre  looks  in  optical  section  like  a  tube — 
hence  the  term  tubular,  formerly  applied  to 
these  fibres.  Two  partial  breaches  of  con- 
tinuity are  seen  in  the  medullary  sheath, 
which  at  these  places  exhibits  a  tendency  to 
split  into  lamina;.  The  primr 
here  and  there  apparent  outside  the  medul- 
lary sheath,  and  the  delicate  striae  which 
are  visible  :  the  fibre  pro- 

bably indicate  the  fibrillated  aiis-cy'.inder. 


Fig.  &4. — Two  portions  of  m  emulated 

NERVE-FIBRE-.  AFTER  TREATMENT 

Willi  OSMIC  A<  II',  3HOWE5G  THE  AXJS- 
i  VLINIiER.  AND  THE  MEDULLARY  AND 
PRIMITIVE    -HEATHS. 

of  Ranvier.    B.  Middle  of  an  inter- 
node   with  nucleus,    c,  axis-cylinder,  pro- 
jecting :  /•.  primitive  sheath,  within  which 
•  stained  dark 
by  the  osmic  acid,  is  somewhat  retracted. 


XERVE-FLBRES  7x 

course  of  the  peri- 
pheral nerve-fibres, 
the  axis-cylinder  at 
these  places  being 
encompassed  only  by 
the  primitive  sheath. 
Hence  the  primitive 
sheath  appears  at 
these  spots  to  pro- 
duce a  constriction 
in  the  nerve- fibre, 
and  the  interruptions 
of  the  medullary 
sheath  are  accord- 
ingly known  as  the 
constrictions  or  nodes 
of  Banvier  ifig.  81, 
b,  r  ;  fig.  83,  li,  the 
term  nodes  being  ap- 
plied from  the  resem- 
blance which  they 
bear  to  the  nodes 
of  a  bamboo.  The 
length  of  nerve  be- 
tween two  successive 
nodes  may  be  termed 
an  intemode  ;  in  the 
middle  of  each  inter- 
node  is  one  of  the 
nuclei  of  Schwann's 
sheath.  Besides 

these  interruptions 
the  medullary  sheath 
shows  a  variable 
number  of  oblique 
clefts  i  fig.  83 1  which 
subdivide  it  into 
irregular  portions, 
which  have  been 
termed  medullary 
segments,  but  there 
is  reason  to  believe 
that  the  clefts  are 
artificially  produced. 
I  -I  Osmic  acid  stains  the 

Fig.   83.  -Nerve-      mecluHarv     sheath 

FIBRE  STAINED 

with  osmic  acid,     black. 


72 


THE   ESSENTIALS  OF   HISTOLOGY 


The  axis-cylinder,  which  runs  along  the  middle  of  the  nerve-fibre, 
is  a  soft  transparent  thread  which  is  continuous  from  end  to  end  of 
the  nerve. 

On  account  of  the  peculiar  refractive  power  of  the  medullary  sheath 


Fig.  85.  —  AXIS- 
CYLINDER,  HIGHLY 
MAGNIFIED,  SHOW- 
ING THE  FIBRILS 
COMPOSING   IT. 


Fig.  86.  —  Portion  of  the 
network  of  fibres  of 
remak  from  the  i'neumo- 
gastric  of  the  dog. 

n,  nucleus ;  p,  protoplasm  sur- 
rounding- it ;  b,  striation  caused 
by  fibrils. 


Fig.  87. — A  small  bi-ndle  of 

NERVE-FIBRES       FROM       THE 
SYMPATHETIC  NERVE. 

The  bundle  is  composed  of  pale 
nerve-fibres,  with  the  exception 
of  the  fibre  m.  m.  which  is  en- 
closed here  and  there  by  a  thin 
medullary  sheath ;  n,  n,  nuclei 
of  pale  fibres. 


it  is  difficult  to  see  the  axis-cylinder  in  the  fresh  nerve  except  at  the 
nodes,  where  it  may  be  observed  stretching  across  the  interruptions  in 
the  medullary  sheath,  andit  may  also  sometimes  be  seen  projecting 
from  a  broken  end  of  a  nerve-fibre.  It  is  longitudinally  striated,  being 
really  made  up  of  exceedingly  fine  fibrils  (ultimate  fibrils,  fig.  85), 
which  are  darkly  stained  by  chloride  of  gold.     Staining  with  nitrate 


STRUCTURE   OF   NERVE-FIBRES 


73 


of  silver  produces  a  curious  transversely  striated  appearance  in  the  axis- 
cylinder,  but  it  is  not  known  if  this  indicates  a  pre-existent  structure. 
Intermingled  with  the  medullated  fibres  there  may  always,  even  in 
the  cerebro-spinal  nerves,  be  found  a  certain  number  of  pale  fibres  devoid 
of  the  dark  double  contour  which  is  characteristic  of  the  presence  of 
a  medullary  sheath.  There  are  the  non-medullated  fibres,  also  called, 
after  their  discoverer,  fibres  o/Bemak  I  fig.  86 1.  They  frequently  branch, 
which  the  medullated  fibres  never  do  except  near  their  termination, 
and  they  are  beset  with  numerous  nuclei  which  perhaps  belong  to  a 
delicate  sheath.  The  sympathetic  nerve  is  in  many  animals  chiefly 
made  up  of  fibres  of  this  nature,  but  in  some  animals,  on  the  other 
hand,  most  of  the  fibres  of  the  sympathetic  possess  some  small  amount 
of  medullary  sheath  (fig.  87). 


Fig.  88. — Section  of  the  saphenous  nerve  (human),  hade  after  being 
stained  in  osm1c  acid  and  subsequently  hardened  in  alcohol. 
(Drawn  as  seen  under  a  very  low  magnifying  power.) 

ep,  epineurium.  or  general  sheath  of  the  nerve,  consisting  of  connective-tissue  bundles  of 
variable  -iz.  separated  by  cleft-like  areolas,  which  appear  as  a  network  of  clear  lines  with 
here  ami  there  fat-cells  ami  blood-vessels  :  /,  /,  funiculi  enclosed  in  their  lauiellated 
connective-tissue  sheaths  (perineurium,  /') :  rnd.  interior  of  funiculus,  showing  the  cut 
ends  of  the  medullated  nerve-fibres,  which  are  embedded  in  the  connective  tissue  within 
the  funiculus  (endoneurium  >.  The  fat-cells  and  the  nerve-fibres  are  darkly  stained  by  the 
osmic  acid,  but  the  connective  tissue  of  the  uerve  is  only  slightly  stained. 


Structure  of  the  nerve-trunks. — In  their  course  through  the  body 
the  nerve-fibres  are  gathered  up  into  bundles  or  funiculi,  and  the 
funiculi  may  again  be  united  together  to  form  the  nerves  which  we 
meet  with  in  dissection.     The   connective   tissue  which   unites  the 


74 


THE   ESSENTIALS   OF   HISTOLOGY 


funiculi  and  invests  the  whole  nerve,  connecting  it  to  neighbouring 
parts  and  conveying  to  it  blood-vessels,  lymphatics,  and  even  nerve- 
fibres  destined  for  its  coats,  is  termed  the  epineurium  (fig.  88,  ep). 
That  which  ensheaths  the  funiculi  is  known  as  the  perineurium  (fig. 
88,  per).     It  has  a  distinctly  lamellar  structure  (fig.  89,  p),  the  lamella? 


Fig.  89. — Part  of  a  section  of  one  of  the  funiculi  of  the  sciatic  nerve 
of  man.     (Magnified.) 

P,  perineurium,  consisting  of  a  number  of  closely  arranged  lamella?.  En,  processes  from  the 
perineurium,  passing  into  the  interior  of  the  funiculus,  and  becoming  continuous  with  the 
endoneurium,  or  delicate  connective  tissue  between  the  nerve-fibres.  The  connective- 
tissue  fibrils  of  the  endoneurium  are  seen  cut  across  as  fine  points,  often  appearing  to  en- 
sheath  the  nerve-fibres  with  a  circle  of  minute  dots  (fibril-sheath  of  Key  and  Retzius). 
Numerous  nuclei  of  connective-tissue  cells  are  embedded  in  the  endoneurium  ;  r,  section 
of  a  blood-vessel. 

being  composed  of  connective  tissue  and  covered  on  both  surfaces  by 
flattened  epithelioid  cells  (fig.  90).  Between  the  lamella?  are  clefts  for 
the  conveyance  of  lymph  to  the  lymphatics  of  the  epineurium.  The 
delicate  connective  tissue  which  lies  between  the  nerve-fibres  of  the 
funiculus  is  the  endoneurium  (fig.  88,  end;  fig.  89,  En).    It  assists  in 


Fig.  90.  —  Nerve-funiculus 
stained  with  nitrate  of  sil- 
ver, SHOWING  THE  OUTLINES  OF 
EPITHELIOID  CELLS  OF  THE 
PERINEURIUM. 

The  dark  crosses  on  the  nerve-fibres  at 
the  nodes  of  Ranvier  are  due  to  the 
staining  of  the  axis-cylinder  and  of 
a  band  of  intercellular  substance 
which  encircles  the  axis-cylinder  at 
the  node  (.constricting  band  of  Ran, 
vier). 


supporting  the  longitudinally  arranged  meshwork  of  blood-capillaries, 
and  its  interstices  communicate  with  the  lymphatic  clefts  of  the 
perineurium. 

The  nerve- trunks  themselves  receive  nerve-fibres  (nervi  nervorum) 
which  ramify  chiefly  in  the  epineurium  and  terminate  in  this  in  end- 
bulbs. 


75 


LESSON  XVIII. 

STRUCTURE   OF  NERVE-CELLS. 

1.  Tease  in  Farrant's  solution  or  in  dilute  glycerine  a  sniall  piece  of  a  spinal 
ganglion  that  has  been  preserved  with  osinic  acid.  Notice  the  spheroidal 
ganglion -cells ;  their  large  nuclei  and  distinct  nucleoli.  Look  for  cells  which 
still  retain  the  axis-cylinder  process  and  for  T-shaped  junctions  of  nerve- 
fibres  with  this. 

2.  Prepare  a  piece  of  sympathetic  ganglion  in  the  same  way.  Cells  may 
be  foimd  with  three  or  more  axis-cylinder  processes.  If  from  a  rabbit  observe 
that  the  cells  are  bi-nucleated. 

3.  Mount  stained  sections  of  ganglia  in  Canada  balsam.  These  will  serve 
to  show  the  arrangement  of  the  cells  and  fibres  in  a  ganglion  and  the 
nucleated  sheaths  around  the  nerve-cells. 

4.  Tease  out  a  portion  of  the  grey  matter  from  a  piece  of  spinal  cord  that 
has  been  a  day  or  two  in  dilute  chromic  acid  (A  per  cent.).  Before  covering, 
look  for  the  nerve-cells  with  a  low  power,  and  if  possible  get  out  one  or  two 
clear  of  the  surrounding  substance.  Mount  in  water  with  a  thick  hair  under 
the  cover-glass.  Notice  the  large  branching  cells  some  with  a  mass  of  pig- 
ment near  the  nucleus.  Observe  the  fibrillation  of  the  cell-processes.  Notice 
also  the  reticular  character  of  the  tissue  in  which  the  cells  are  embedded. 
Many  axis- cylinders  will  be  seen  in  this  preparation  deprived  wholly  or 
partially  of  their  medullary  sheath,  and  their  fibrillar  structure  can  then  also 
be  well  seen.  Carefully  sketch  these  appearances.  To  keep  this  preparation 
run  very  dilute  logwood  solution  or  osmic  acid  under  the  cover-glass,  and 
when  the  cells  are  stained  allow  a  drop  of  glycerine  to  pass  in  by  diffusion. 

Measure  two  or  three  cells  in  each  of  the  above  preparations. 


Nerve-cells  only  occur  in  the  grey  matter  of  the  nerve-centres,  and 
in  little  groups  on  the  course  of  certain  of  the  peripheral  nerves,  these 
groups  often  causing  nodular  enlargements  of  the  nerves,  which  are 
known  as  ganglia.  The  most  important  ganglia  are  those  which  are 
found  upon  the  posterior  roots  of  the  spinal  nerves,  upon  the  roots  of 
some  of  the  cranial  nerves,  and  upon  the  trunk  and  principal  branches 
of  the  sympathetic  nerve.  Minute  ganglia  are  also  found  very  nume- 
rously in  connection  with  the  nerves  which  are  supplied  to  involuntary 
muscular  tissue,  as  in  the  heart,  alimentary  canal,  bladder,  uterus,  £c. 

Nerve-cells  vary  much  in  size  and  shape  ;  they  are  mostly  large, 
some  being  amongst  the  largest  cells  met  with  in  the  body,  but 
others  are  quite  small.     The  nucleus  is  generally  large,  clear,   and 


76 


THE   ESSENTIALS   OF   HISTOLOGY 


spherical,  with  a  single  large  and  distinct  nucleolus.  The  shape 
depends  a  good  deal  on  the  number  of  processes,  and  the  manner 
in  which  they  come  off  from  the  cell.  If  there  is  but  one  process, 
the  cell  is  generally  spherical.     This  is  the  case  with  the  cells  of  the 


Fig.  91. — Cell  from  a  spinal  ganglion. 

sh,  nucleated  sheath  of  the  cell ;  11,  »',  the  nerve-fibre  which  the  single  process  of  the  cell, 
after  a  number  of  coils,  joins. 


Fig  92. — Ganglion-cell  of  a 
frog,  highly  magnified. 

a,  a,  straight  fibre ;    b.  b.  coiled  fibre ; 
c,  smaller  one  joining  it. 


Fig.    93.  —  A     ganglion-cell    ■within     its 

SHEATH  ;    FROM     THF.     HUMAN    SYMPATHETIC. 

(Highly  magnified.) 


spinal  ganglia  (fig.  91)  ;  in  these  the  single  process,  after  a  short 
course,  joins  one  of  the  nerve-fibres  which  is  traversing  the  ganglion. 
When  there  are  two  processes,  they  often  go  off  in  opposite  directions 


STRUCTURE   OF  NERVE-CELLS 


77 


from  the  cell,  which  is  thus  rendered  somewhat  spindle-shaped,  but 
occasionally  they  emerge  at  the  same  part,  and  the  cell,  being  tapered 
in  their  direction,  becomes  pyriform  (fig.  92).  In  these  cases  one  fibre 
often  coils  spirally  round  the  other  (fig.  92,  b)  before  they  separate  to 
proceed  in  opposite  directions  as  the  axis-cylinders  of  nerve-fibres. 
When  there  are  three  or  more  processes,  the  cell  becomes  irregularly 
angular  or  stellate.  Sometimes,  as  in  the  sympathetic  ganglia  (fig.  93), 
all  the  processes  appear  to  become  nerve-fibres,  but  in  other  instances, 
as  in  the  large  cells  of  the  grey  matter  of  the  spinal  cord,  only  one 


Fig.  94. — Nerve-cell  from  spinal  cord  of  ox,  isolated  after  maceration 
in  very  dilute  chromic  acid.     (Magnified  1~5  diameters.) 

The  cell  has  a  well-defined,  clear,  round  nucleus,  and  a  bright  nucleolus.  The  cell  processes 
are  seen  to  be  finely  fibrillated,  the  fibrils  passing  from  one  process  into  another  through 
the  body  of  the  cell,    «,  axis-cylinder  process  broken  a  short  distance  from  the  cell. 


process  becomes  the  axis-cylinder  of  a  nerve-fibre  (process  of  Deiters), 
the  others  dividing  and  subdividing  in  a  ramified  manner  until  their 
further  course  can  no  longer  be  traced.  Their  ultimate  branches 
appear  to  lose  themselves  in  a  network  which  pervades  the  whole  of 
the  grey  matter. 

According  to  the  number  of  their  processes,  nerve-cells  are  termed 
uni-,  bi-,  or  multi-polar. 

Many  nerve-cells,  and  notably  those  of  the  spinal  cord,  have  a  finely 
fibrillar  structure.  The  fibrils  can  be  traced  into  the  branches  of  the 
cells  and  into  the  axis-cylinders  of  nerve-fibres  which  are  connected 
with  the  cells  (fig.  95).  Otherwise  the  cells  have  a  finely  granular 
appearance  ;  often  with  a  clump  of  black,  brown,  or  yellow  pigment- 
granules  placed  at  one  side  of  the  nucleus. 


78 


THE   ESSENTIALS   OF  HISTOLOGY 


In  the  ganglia  the  nerve-cells  have  a  nucleated  sheath  (figs.  91- 
93)  which  is  continuous  with  the  primitive  sheath  of  the  nerve-fibres 
with  which  they  are  connected.  In  the  spinal  ganglia,  and  in  many  of 
the  ganglia  at  the  roots  of  the  cranial  nerves,  the  cells  are  unipolar, 


:,r  :]'■ 


Fig.  95. — Axis-cylinder 
process  of  nerve- 
CELL. 

x,  x,  portion  of  nerve- 
cell  ;  a,  axis-cylinder 
process ;  a',  medullary 
sheath.  Highly  magni- 
fied. 


and  the  cell-process  joins  a  traversing  nerve-fibre  by  a  T-shaped 
junction  (fig.  91).  In  the  sympathetic  ganglia  they  are  multipolar. 
The  cells  are  disposed  in  aggregations  of  different  size,  separated  by 
the  bundles  of  nerve-fibres  which  are  traversing  the  ganglion  (fig.  96). 


STRUCTURE   OF  NERVE-CELLS 


79 


The  ganglion  if  large  is  enclosed  by  an  investing  capsule  of  connective 
tissue  which  is  continuous  with  the  epi-  and  peri-neuriuni  of  the 
entering  and  issuing  nerve-trunks. 

The  structure  of  the  nerve-centres  and  the  arrangement  of  the 
cells  and  fibres  in  them  are  given  hi  Lessons  XXXVI.  to  XXXIX. 


Fjg.  96. — Longitudinal  section  through  the  middle  of  a  ganglion  on 
the  posterior  root  ok  one  of  the  sacral  nerves  of  the  dog,  as 
seen  under  a  low  magnifying  rower. 

a,  nerve-root  entering  the  ganglion  :  b,  fibres  leaving  the  ganglion  to  join  the  mixed  spinal 
nerve;  r.  connective-tissue  coat  of  the  ganglion;  d,  principal  group  of  nerve-cells,  with 
fibres  passing  down  from  amongst  the  cells,  probably  to  unite  with  the  longitudinally 
coursing  nerve-fibres  by  T-shaped  junctions. 


Development. — The  cells  and  fibres  of  the  nervous  tissue  are 
developed  from  cells  derived  from  the  ectoderm  or  epiblast  of  the  embryo. 
The  nerve-fibres  are  at  first  developed  as  pale  fibres  like  the  fibres 
of  Remak  ;  it  is  uncertain  whether  they  are  formed  by  the  coalescence 
of  a  number  of  cells,  or  whether  they  grow  out  as  the  processes  of 
nerve-cells.     The  medullary  sheath  is  subsequently  added. 

When  a  nerve  is  cut,  the  fibres  beyond  the  section  as  far  as  their 
terminations  undergo  a  process  of  degeneration,  the  medullary  sheath 
being  broken  up  and  the  axis-cylinder  interrupted  and  eventually 
absorbed.  New  nerve-fibres  are  at  length  produced  by  a  growth  of  the 
axis-cylinders  in  the  proximal  end  of  the  nerve. 


80  THE   ESSENTIALS   OF  HISTOLOGY 


LESSON   XIX. 

MODES   OF  TERMINATION  OF  NERVE-FIBRES. 

1.  Shell  out  a  Pacinian  corpuscle  from  a  piece  of  cat's  mesentery  which  has 
been  kept  for  two  or  three  days  in  -71-  per  cent,  chromic  acid,  and  clear  it  as 
much  as  possible  of  adhering  fat,  but  be  careful  not  to  prick  or  otherwise 
injure  the  corpuscle  itself.  Mount  in  water  with  a  thick  hair  to  prevent 
crushing  with  the  cover-glass.  Sketch  the  corpuscle  under  a  low  power,  and 
afterwards  draw  under  a  high  power  the  part  of  the  core  where  the  nerve 
enters  and  the  part  where  it  terminates.  Notice  the  fibrous  structure  of  the 
lamellar  tunics  of  the  corpuscle  and  the  oval  nuclei  belonging  to  flattened 
epithelioid  cells  which  cover  the  tunics.  The  distinct  lines  which  when  seen 
in  the  fresh  corpuscle  are  generally  taken  for  the  tunics,  are  really  the  optical 
sections  of  these  flattened  cells. 

2.  Mount  in  Farrant  one  or  more  sections  of  a  rabbit's  cornea  which  has 
been  stained  with  chloride  of  gold.  Notice  the  arrangement  in  plexuses  of 
the  darkly  stained  nerve-fibres  and  fibrils,  (1)  in  the  connective-tissue  sub- 
stance, (2)  under  the  epithelium  and  (3)  between  the  epithelial  cells.  Make 
one  or  two  sketches  showing  the  arrangement  of  the  fibrils. 

3.  Spread  out  a  small  piece  of  muscle  which  has  been  stained  with 
chloride  of  gold  by  Lowit's  method,  and  examine  it  with  a  low  power  to  find 
the  nerve-fibres  crossing  the  muscular  fibres  and  distributed  to  them. 

Try  and  separate  those  parts  of  the  muscular  fibres  to  which  nerves 
appear  to  go,  and  mount  them  in  glycerine.  Search  thoroughly  for  the  close 
terminal  ramifications  (end-plates)  of  the  axis -cylinders  immediately  within 
the  sarcolemma. 

It  is  rather  difficult  to  dissociate  the  fibres,  and  much  patience  is  some- 
times required  in  searching  for  the  nerve-terminations,  but  when  they  are 
found  the  trouble  is  amply  repaid.1 


Modes  of  ending  of  sensory  nerve-fibres. — Nerve-fibres  which  are 
distributed  to  sensory  parts  end  either  in  special  organs  or  in  terminal 
ramifications  or  plexuses.  There  are  three  chief  kinds  of  special 
organs,  termed  respectively  Pacinian  corpuscles,  tactile  corpuscles,  and 
end-bulbs.  In  the  tactile  corpuscles  and  end-bulbs  the  connective- 
tissue  sheath  of  a  medullated  fibre  expands  to  form  a  somewhat  solid 
bulbous  enlargement,  which  is  either  cylindrical  or  spheroidal  in  the 
end-bulbs  and  ellipsoidal  in  the  tactile  corpuscles.  Li  both  kinds  of  end- 
organ  there  is  a  capsule  of  connective  tissue  within  which  is  generally 
a  sort  of  core  containing  numerous  nucleated  cells.  As  the  nerve-fibre 
enters  the  corpuscle  (which  in  the  tactile  corpuscle  only  happens  after 
it  has  reached  the  distal  part  of  the  corpuscle  having  wound  spirally 
1  For  methods  of  staining  with  chloride  of  gold  see  Appendix. 


MODES  OF   TERMINATION  OF  NERVE-FIBRES 


81 


once  or  twice  round  it)  it  loses  its  sheaths  and  is  prolonged  as  an  axis- 
cylinder  only,  which  terminates  after  either  a  straight  or  a  convoluted 
course  within  the  organ  (see  figs.  98  to  101).     Tactile  corpuscles  occur 


Fig.  97. — Section  of  skin  showing  two  papill.e  and  deeper  layers  of 
epidermis. 

a,  vascular  papilla  with  capillary  loop  passing  from  subjacent  vessel,  c  ;  6,  nerve-papilla  with 
tactile  corpuscle,  t.  The  latter  exhibits  transverse  fibrous  markings  ;  d,  nerve  passing  up 
to  it  ;  /,  /,  sections  of  spirally  winding  nerve-fibres. 


Ep 


Fig.  08.— Tactile  corpuscle 
within  a  papilla  of  the 
>kin  <  >f  the  hand,  stained 
with  chloride  of  gold. 

The  convolutions  of  the  nerve- 
fibres  within  the  corpuscle  are 
seen.    Ep.  epidermis. 


Fig.  99. — Simple  tactile 
end-organs    prom  the 

clitoris  of  the  rabbit. 


Fig.  ino._ Cylindrical 

END-BULR  FROM  THE 
CONJUNCTIVA  OF  THE 
CALF. 


82 


THE  ESSENTIALS  OF  HISTOLOGY 


Fig.  101. — End-bulb  from  the  human 
conjunctiva. 

a,  nucleated  capsule ;  b,  core,  the  outlines  of 
its  cells  are  not  seen :  c.  entering  fibre, 
branching,  and  its  two  divisions  passing  to 
terminate  in  the  core  at  d. 


Fig.  102. — Tactile  corpuscles  from  the 
duck's  tongue. 

A,  composed  of  three  cells,  with  two  interposed 
disks,  into  which  the  axis-cylinder  of  the  nerve, 
n,  is  observed  to  pass;  inB  there  is  but  one 
tactile  disk  enclosed  between  two  tactile  cells. 


Fig.  103.— Magnified  view  of  a 
Pacinian*  body  from  the  cat's 
mesentery. 

s.   stalk  with  nerve-fibre  passing   to   the 
corpuscle.    One  or  two  capillaries  are 
seen  issuing  from  it  between  the 
tunics. 


Fig.  104. — Part  of  Pacinian  body,  showing 
the  nerve-fibres  entering  the  core. 
From  an  osmic  acid  preparation. 

ms,  entering  nerve-fibre,  the  medullary  sheath  of 
which  is  stained  darkly,  and  end-  abruptly  at  the 
core;  ps,  prolongation  of  primitive  -heath,  passing 
towards  the  outer  part  of  the  core:  e.f.  axis-cylin- 
der passing  through  the  core  of  the  central  fibre: 
e,  -"me  of  the  inner  tunics  of  the  corpuscle,  enlarged 
where  they  abut  against  the  canal  through  which 
the  nerve-fibre  passes — the  dots  within  them  are 
sections  of  the  fibres  of  which  they  are  composed ; 
n.  nuclei  of  the  tunics:  n',  nuclei  of  the  endo- 
neurium,  continued  by  others  in  the  outer  part  of 
the  core. 


MODES  OF  TERMINATION  OF  NERVE-FIBRES  83 

in  some  of  the  papilla?  of  the  skin  of  the  hand  and  foot,  in  sections  of 
which  they  may  be  afterwards  studied  (see  Lesson  XXIII.)  End- bulbs 
are  found  in  the  conjunctiva  of  the  eye,  where  in  most  animals  they 
have  a  cylindrical  or  oblong  shape  (fig.  100),  but  in  man  are  spheroidal 
(fig.  101).  They  have  also  been  found  in  papilla?  of  the  lips  and 
tongue,  and  in  the  epineurium  of  the  nerve -trunks,  and  somewhat 
similar  sensory  end- organs  also*  occur  in  the  integument  of  the  external 
genital  organs  of  both  sexes  (fig.  99).  In  the  skin  covering  the  bill, 
and  in  the  tongue  of  certain  birds  (e.g.  duck),  a  simple  form  of  end- 
organ  occurs,  consisting  of  two  or  more  cells  arranged  in  rows  within 
a  capsule,  with  the  axis-cylinder  terminating  in  flattened  expansions 
between  the  cells  (corpuscles  of  Grandry,  fig.  102). 

The  Pacinian  corpuscles  are  larger,  and  have  a  more  complex 
structure,  than  the  tactile  corpuscles  and  end-bulbs  (fig.  103).  They 
are  composed  of  a  number  of  concentric  coats  arranged  like  the  layers 
of  an  onion,  and  enclosing  the  prolonged  end  of  a  nerve-fibre.  A  single 
medullated  nerve -fibre  goes  to  each  Pacinian  corpuscle  encircled  by 
a  prolongation  of  perineurium,  and  within  this  by  endoneurium  ;  when 
it  reaches  the  corpuscle,  of  which  it  appears  to  form  the  stalk,  the 
lamellae  of  the  perineurium  expand  to  form  some  of  the  tunics  of  the 
corpuscle.  The  nerve  passes  on,  piercing  the  other  tunics,  and  still 
provided  with  medullary  sheath,  and  surrounded  by  endoneurium,  to 
reach  the  centre  of  the  corpuscle.  Here  the  endoneurium  is  prolonged 
to  form  a  sort  of  soft  cylindrical  core,  along  the  middle  of  which  the 
nerve-fibre,  now  deprived  of  its  medullary  and  primitive  sheaths,  passes 
in  a  straight  course  as  a  simple  axis-cylinder  (fig.  104,  c.f.)  to  termi- 
nate at  the  farther  end  of  the  core  in  a  bulbous  enlargement.  Occa- 
sionally the  fibre  is  branched. 

The  tunics  of  the  corpuscle  are  composed  of  connective  tissue,  the 
fibres  of  which  for  the  most  part  run  circularly.  They  are  covered  on 
both  surfaces  with  a  layer  of  flattened  epithelioid  cells,  and  here  and 
there  cleft-like  lymph-spaces  can  be  seen  between  them  like  those 
between  the  layers  of  the  perineurium  (see  p.  74  I. 

When  sensory  nerve-fibres  terminate  in  plexuses,  they  generally 
branch  once  or  twice  on  nearing  their  termination.  The  sheaths  of  the 
fibres  then  successively  become  lost,  first  the  connective  tissue  or  peri- 
neural sheath,  then  the  medullary  sheath,  and  lastly  the  primitive 
sheath,  the  axis-cylinder  being  alone  continued  as  a  bundle  of  primitive 
fibrils  (fig.  105,  n).  This  branches  and  joins  with  the  ramifications 
of  the  axis-cylinders  of  neighbouring  nerve-fibres  to  form  a  primary 
plexus.  From  the  primary  plexus  smaller  branches  (a)  come  off,  and 
these  form  a  secondary  plexus  (e)  nearer  the  surface,  generally  imme- 
diately under  the  epithelium  if  the  ending  is  in  a  membrane  covered  by 
that  tissue.  Finally,  from  the  secondary  plexus  nerve-fibrils  proceed 
and  form  a  terminal  plexus  or  ramification  amongst  the  epithelium- 
cells  i fig.  10(3,  p),  the  actual  ending  of  the  fibrils  being  generally  in 
little  knob-like  enlargements  (b).     Such  a  mode  of  ending  in  terminal 

o2 


84 


THE  ESSENTIALS  OF  HISTOLOGY 


*«*£S3ggg! 


Fio.  105. — Sub-epithelial  plexus  of  the  cornea  treated  with  chloride  of 
gold.     (Ranvier.) 

n,  branch  of  primary  plexus ;  a,  small  branch,  passing  to  join  the  sub-epithelial  plexus,  e. 


Fig.  106  — Vertical  section  of  cornea  stained  with  chloride  of  gold. 

(Ranvier.) 

n,  r,  primary  plexus  in  connective  tissue  of  cornea  ;  a,  branch  passing  to  sub-epithelial  plexus,  s ; 
p,  intra-epithelial  plexus  ;  b,  terminations  of  fibrils. 


MODES   OF   TERMINATION   OF  NERVE-FIBRES 


85 


plexuses  is  most  characteristically  seen  in  the  cornea  of  the  eye.  The 
nerve-fibrils  may  be  brought  distinctly  into  view  by  staining  with 
chloride  of  gold,  and  then  the  fibrillar  structure  of  the  ramifications  of 
the  axis-cylinders  also  becomes  very  apparent. 


Fig.  107. — Nerve-ending  in  muscular  fibre  of  a  lizard  (Lacerta 
viridis) 

a,  end-plate  seen  edgeways  ;  6,  from  the  surface  ;  s,  s,  sarcolemma  ;  p,  p,  expansion  of  axis- 
cylinder.  In  6  the  expansion  of  the  axis-cylinder  appears  as  a  clear  network  branching 
from  the  divisions  of  the  medullated  fibres. 


Fig.  108. — Terminal  ramifications  of  the  axis-cylinder  in  end-plates 
of  muscle,  stained  with  chloride  of  gold.    (Ranvier.) 


Ending  of  motor  nerves. — Lastly  the  nerves  to  muscles  also  ter- 
minate either  in  special  organs  or  in  plexuses.  The  latter  is  the  case 
with  the  nerves  going  to  involuntary  muscle,  and  here  the  primary 
plexuses  are  generally  furnished  with  ganglion-cells  in  abundance. 
From  these  other  nerve-fibres  pass  which  form  secondary  plexuses  and 
terminal  ramifications  amongst  the  contractile  fibre-cells.  These 
nerves  will  be  more  fully  studied  in  connection  with  the  intestine  (see 
Lesson  XXIX.  i 


86  THE   ESSENTIALS  OF   HISTOLOGY 

In  voluntary  muscle  the  nerves,  which  are  always  rnedullated,  ter- 
minate in  special  organs,  the  so-called  end-plates.  A  rnedullated  fibre 
will  branch  two  or  three  times  before  terminating,  and  then  each 
branch  passes  straight  to  a  muscular  fibre.  Having  reached  this,  the 
primitive  sheath  of  the  nerve-fibre  is  continued  into  the  sarcolemma  of 
the  muscle,  the  medullary  sheath  stops  short,  and  the  axis-cylinder 
ends  in  a  close  terminal  ramification  with  varicosities  upon  its  branches 
(figs.  107,  108).  This  ramification  is  embedded  in  a  granular  nucleated 
protoplasmic  mass  which  lies*  between  the  sarcolemma  and  the  cross- 
striated  muscular  substance.  In  some  cases  the  ramification  is 
restricted  to  a  small  portion  of  the  muscular  fibre,  and  forms  with  the 
granular  bed  a  slight  prominence  (eminence  of  Doyere).  This  is  the 
case  in  mammals.  In  the  lizard  the  ramification  is  rather  more 
extended  than  in  mammals,  whilst  in  the  frog  it  is  spread  over  a 
considerable  length  of  the  fibre. 


87 


LESSON   XX. 

STRUCTURE  OF  THE   LARGER  BLOOD-VESSELS. 

1.  Sections  of  a  medium-sized  peripheral  artery  and  vein.  In  this  pre- 
paration the  limits  of  the  vascular  coats  can  be  well  seen  and  also  the  differ- 
ences which  they  present  in  the  arteries  and  veins  respectively.  The  sections 
may  either  be  stained  with  hematoxylin  and  mounted  in  Canada  balsam,  or 
they  may  be  stained  in  dilute  magenta  anil  mounted  in  glycerine  and  water. 

2.  Mount  in  Canada  balsam  a  thin  slice  cut  from  the  inner  surface  of  an 
artery  which,  after  having  been  cut  open  longitudinally  and  washed  with 
distilled  water,  has  been  treated  with  nitrate  of  silver  solution  and  exposed  to 
the  light  in  spirit.  This  preparation  will  show  the  outlines  of  the  epithelioid 
cells  which  line  the  vessel. 

3.  A  piece  of  an  artery  which  has  been  macerated  for  two  or  three  days 
in  30  per  cent,  alcohol  (1  part  rectified  spirit  to  two  pai-ts  water  i  is  to  be 
teased  so  as  to  isolate  some  of  the  muscular  cells  of  the  middle  coat  and 
portions  of  the  elastic  layers  (networks  and  fenestrated  membranes)  of  the 
inner  and  middle  coats.  The  tissue  may  be  stained  cautiously  with  dilute 
logwood  solution,  and  glycerine  afterwards  added.     The  muscular  cells  are 

usable  by  their  irregular  outline  and  long  rod-shaped  nucleus.     Sketch 
one  or  two  and  also  a  piece  of  fenestrated  membrane. 

4.  Transverse  section  of  aorta.  Notice  the  differences  in  structure 
between  this  and  the  section  of  the  smaller  artery. 

5.  Transverse  section  of  vena  cava  inferior.  Notice  the  comparatively 
thin  layer  of  circular  muscle,  and  outside  this  the  thick  layer  of  longitudinal 
muscular  bundles. 

Make  sketches  from  1,  4,  and  5,  under  a  low  power,  from  2  and  3  under 
a  high  power. 


An  artery  is  usually  described  as  being  composed  of  three  coats, 
an  inner  or  elastic,  a  middle  or  muscular,  and  an  external  or  areolar 
(fig.  109,  b,  c,  d).  It  would,  however,  be  more  correct  to  describe  the 
wall  of  an  artery  as  being  composed  of  muscular  and  elastic  tissue 
lined  internally  by  a  pavement-epithelium  and  strengthened  externally 
by  a  layer  of  connective  tissue.  For  the  present,  however,  we  may 
adhere  to  the  generally  received  mode  of  description.  The  inner  coat 
of  an  artery  is  composed  of  two  principal  layers.  The  inner  one  is  a 
thin  layer  of  pavement-epithelium  I  often  spoken  of  as  the  endothelium  i. 
the  cells  of  which  are  somewhat  elongated  in  the  direction  of  the  axis 
of  the  vessel  (fig.  110),  and  form  a  smooth  lining  to  the  tube.  After 
death  they  become  easily  detached.     Next  to  this  comes  an  elastic 


88 


THE  ESSENTIALS   OF  HISTOLOGY 


layer  in  the  form  either  of  elastic  networks  or  of  a  fenestrated  mem- 
wane.  In  some  arteries  there  is  a  layer  of  fine  connective  tissue  in- 
tervening between  the  epithelium  and  the  fenestrated  membrane  (sub- 
ejntlielial  layer). 


i*~: 


Fig.  109. — Transverse  section  of  part  of  the  wall  of  the  posterior  tibial 
artery.     (75  diameters.) 

a,  epithelial  and  subepithelial  layers  of  inner  coat ;  5,  elastic  layer  (fenestrated  membrane)  of 
inner  coat,  appearing  as  a  bright  line  in  section  ;  c,  muscular  layer  (middle  coat) ;  d,  outer 
coat,  consisting  of  connective-tissue  bundles.  In  the  interstices  of  the  bundles  are  some 
connective-tissue  nuclei,  and,  especially  near  the  muscular  coat,  a  number  of  elastic  fibres 
cut  across. 


Fig.  110. — Epithelial  layer  lining 

the  posterior  tibial  artery. 

(250  diameters.) 


Fig.  111. — Portion  of  fenestra- 
ted membrane  from  an  artery. 
(Toldt.) 

«.  b,  c,  perforations. 


The  middle  coat  consists  mainly  of  circularly  disposed  plain  mus- 
cular fibres,  but  it  is  also  pervaded  in  most  arteries  by  a  network  of 
elastic  fibres  which  are  connected  with  the  fenestrated  membrane  of 
the  inner  coat  and  are  sometimes  almost  as  much  developed  as  the 
muscular  tissue  itself.  This  is  especially  the  case  with  the  larger 
arteries  such  as  the  carotid  and  its  immediate  branches,  but  in  the 
smaller  arteries  of  the  limbs  the  middle  coat  is  almost  purely  composed 
of  muscular  tissue. 


STRUCTURE   OF  THE   LARGER   BLOOD-VESSELS 


89 


The  outer  coat  is  formed  of  connective  tissue  with  a  good  mam- 
elastic  fibres,  especially  next  the  middle  coat.  The  strength  of  an 
artery  depends  largely  upon  this  coat ;  it  is  far  less  easily  cut  or  torn 
than  the  other  coats,  and  it  serves  to  resist  undue  expansion  of  the 


Fig.  112. — Elastic  net- 
work OF  ARTERY. 

(Toldt.) 


Fig.  1 13. — Muscular  fibre-cells  from 
superior  thyroid  artery.  (340 
diameters.) 


Fig.  114. — Section  of  thoracic  aorta  as  sei  n  inhkii  a  low  power.  (Toldt.) 

a,  the  inner  coat  consisting  of  three  layers,  viz.  :  1.  Epithelium  seen  a?  a  fine  line.  2.  Sub- 
epithelial. 3.  Elastic  layers.  In  tin-  part  of  the  inner  coat,  at  its  junction  with  the 
middle, a  layer  of  longitudinal  muscular  fibres  i-  represented  as  cut  aero--,  b,  middle  coat 
with  its  elastic  membranes  ;  c,  outer  coat  with  two  va-a  vasorum. 


vessel.  Its  outer  limit  is  not  sharply  marked,  for  it  tends  to  blend 
with  the  surrounding  connective  tissue  (hence  it  has  been  termed 
tunica  adventitia). 

Variations    in  structure. — The   aorta    (fig.    114 1  differs   in   some 


90  TPIE   ESSENTIALS   OF   HISTOLOGY 

respects  in  structure  from  an  ordinary  artery.  Its  inner  coat  contains 
a  considerable  thickness  of  sub-epithelial  connective  tissue,  but  its 
clastic  layers  are  chiefly  composed  of  fine  fibres,  and  are  not  especially 
marked  off  from  those  of  the  middle  coat,  so  that  the  inner  and  middle 
coats  appear  almost  blended  with  one  another.  On  the  other  hand,  there 
is  a  very  great  development  of  elastic  tissue  in  the  middle  coat,  this  tissue 
forming  membranous  layers  which  alternate  with  layers  of  the  mus- 
cular tissue.  A  good  deal  of  connective  tissue  also  takes  part  in  the 
formation  of  the  middle  coat,  so  that  the  wall  is  unusually  strong. 
The  inner  and  middle  coats  constitute  almost  the  entire  thickness  of 
the  wall,  the  outer  coat  being  relatively  thin. 

The  other  variations  which  occur  in  the  arterial  system  chiefly 
have  reference  to  the  development  and  arrangement  of  the  muscular 
tissue.  Thus  in  many  of  the  larger  arteries  there  are  longitudinal 
muscular  fibres  at  the  inner  boundary  of  the  middle  coat,  and  in  some 
arteries  amongst  the  circular  fibres  of  the  middle  coat.  This  is  the  case 
in  the  aorta.  In  some  parts  of  the  umbilical  arteries  there  is  a  com- 
plete layer  of  longitudinal  fibres  internal  to  the  circular  fibres  and 
another  external  to  them,  whilst  the  amount  of  elastic  tissue  is  very 
small.  Longitudinal  fibres  are  also  present  in  some  other  arteries 
(iliac,  superior  mesenteric,  splenic,  renal,  &c),  external  to  the  circular 
fibres,  and  therefore  in  the  outer  coat  of  the  artery.  The  larger 
arteries  themselves  receive  blood-vessels,  vasa  vasorum,  which  ramify 
chiefly  in  the  external  coat.  Nerves,  derived  for  the  most  part  from  the 
sympathetic  system,  are  distributed  to  the  muscular  tissue  of  the 
middle  coat. 

The  veins  (fig.  115)  on  the  whole  resemble  the  arteries  in  structure, 
but  they  present  certain  differences.     In  the  internal  coat  the  same 

£^*> 


%*g&8%$£g^ 


Fig.  115. — Transverse  section  of  part  of  the   wall  of  one  of  the  posterior 

TIIilAL   VEINS    (MAN). 

a,  epithelial  and  sub-epithelial  layers  of  inner  coat ;  b,  elastic  layers  of  inner  coat :  c,  middle 
coat  consisting  of  irregular  layers  of  muscular  tissue,  alternating  with  connective  tissue 
and  passing  somewhat  gradually  into  the  outer  connective  tissue  and  elastic  coat,  d. 

layers  may  be  present,  but  the  elastic  tissue  is  less  developed  and  seldom 
takes  the  form  of  a  complete  membrane.  The  epithelium -cells  are 
less  elongated  than  those  of  the  arteries.  The  middle  coat  (c)  contains 
less  elastic  tissue  and  also  less  muscular  tissue,  being  partly  occupied 
by    bundles   of  white    connective-tissue   fibres.      These   are   derived 


STRUCTURE   OF  THE   LARGER  BLOOD-VESSELS  91 

from  the  external  coat,  which  is  relatively  better  developed  in  the  veins 
than  in  the  arteries,  so  that,  although  thinner,  their  walls  are  often 
stronger. 

Many  of  the  veins  are  provided  with  valves,  which  are  semilunar 
folds  of  the  internal  coat  strengthened  by  a  little  fibrous  tissue  :  a  few 
muscular  fibres  may  be  found  in  the  valve  near  its  attachment.  The 
layer  of  the  inner  coat  is  rather  thicker,  and  the  epithelium-cells  are 
more  elongated  on  the  side  which  is  subject  to  friction  from  the  current 
of  blood  than  on  that  which  is  turned  towards  the  wall  of  the  vessel. 

Variations  in  different  veins. — The  veins  vary  in  structure  more  than 
do  the  arteries.  In  many  veins  longitudinal  muscular  fibres  are  found 
in  the  inner  part  of  the  middle  coat,  as  in  the  iliac,  femoral,  umbilical, 
&c.  ;  in  others  they  occur  external  to  the  circularly  disposed  fibres,  and 
are  described  as  belonging  to  the  outer  coat.  This  is  the  case  in  the 
inferior  vena  cava  and  also  in  the  hepatic  veins  and  in  the  portal  vein 
and  its  tributaries.  In  the  superior  and  in  the  upper  part  of  the  inferior 
vena  cava  the  circular  fibres  of  the  middle  coat  are  almost  entirely 
absent.  The  veins  of  the  following  parts  have  no  muscular  tissue, 
viz.  pia  mater,  brain  and  spinal  cord,  retina,  bones,  and  the  venous 
sinuses  of  the  dura  mater  and  placenta. 

It  is  only  the  larger  veins  and  especially  those  of  the  limbs  that 
possess  valves.  They  are  wanting  in  most  of  the  veins  of  the  viscera, 
in  those  within  the  cranium  and  vertebral  canal,  in  the  veins  of  the 
bones,  and  in  the  umbilical  vein. 


92  THE   ESSENTIALS   OF  HISTOLOGY 


LESSON   XXI. 

SMALLER   BLOOD-VESSELS.    LYMPHATIC   SYSTEM. 

1.  Take  a  piece  of  pia  niater  which  has  been  stained  with  logwood,  and 
separate  from  it  some  of  the  sntall  blood-vessels  of  which  it  is  chiefly 
composed.  Mount  the  shreds  in  Farrant.  The  structure  of  the  small 
arteries  can  be  studied  in  this  preparation,  the  nuclei  of  the  epithelium  and 
of  the  muscular  coat  being  brought  distinctly  into  view  by  the  logwood. 
The  veins,  however,  possess  no  muscular  tissue.  Capillary  vessels  which 
have  been  dragged  out  from  the  brain  in  removing  the  pia  mater  may  also 
be  seen  in  this  preparation.  Sketch  two  smaU  arteries  of  different  sizes, 
giving  also  their  measurements. 

2.  Mount  in  Canada  balsam  a  piece  of  the  omentum  of  the  rabbit  stained 
with  silver  nitrate.  The  membrane  should  be  stretched  over  a  cork  or  a 
plate  of  glass,  rinsed  with  distilled  water,  treated  for  five  minutes  with  1  per 
cent,  nitrate  of  silver  solution,  again  washed  and  exposed  to  the  light  in  spirit. 
"When  stained  brown  the  spirit  is  replaced  by  oil  of  cloves.  Pieces  may  now 
be  cut  off  from  the  membrane  and  mounted,  as  directed,  in  Canada  balsam ; 
they  should  include  one  or  more  blood-vessels. 

This  preparation  is  intended  to  show  the  epithelium  of  the  smaller  blood- 
vessels and  accompanying  lymphatics  and  also  the  epithelium  of  the  serous 
membrane.     Sketch  a  small  piece  showing  the  epithelium  of  the  vessels. 

3.  Mount  in  Canada  balsam  a  piece  of  the  central  tendon  of  the  rabbit's 
diaphragm  which  has  been  similarly  prepared  (except  that  the  pleural  surface 
has  first  been  brushed  to  remove  the  superficial  epithelium  so  as  to  enable 
the  nitrate  of  silver  more  readily  to  penetrate  to  the  network  of  lymphatic 
vessels  underlying  that  surface).  Observe  the  lymphatic  plexus  under  a  low 
power  :  sketch  a  portion  of  the  network.  If  the  peritoneal  surface  is  focussed, 
the  epithelium  which  covers  that  surface  will  be  seen,  and  opposite  the  clefts 
between  the  radially  disposed  tendon-bundles  stomata  may  be  looked  for  in 
this  epithelium. 

4.  Carefully  study  the  circulation  of  the  blood  either  in  the  web  of  the 
frog"s  foot  or  in  the  mesentery  or  tongue  of  the  frog  or  toad,  or  in  the  tail  of 
the  tadpole. 


The  coats  of  the  smaller  arteries  and  veins  are  much  simpler  in 
structure  than  those  of  the  larger  vessels,  but  they  contain  at  first  all 
the  same  elements.  Thus  there  is  a  lining  epithelium  and  an  elastic 
layer  forming  an  inner  coat,  a  middle  coat  of  circularly  disposed  plain 
muscular  tissue,  and  a  thin  outer  coat.  The  same  differences  also  are 
found  between  the  arteries  and  veins,  the  walls  of  the  veins  being 
thinner  and  containing  far  less  muscular  tissue  (fig.  116),  and  the 
lining  epithelium-cells,  much  elongated  in  both  vessels,  are  far  longer 


SMALLER  BLOOD-VESSELS 


93 


and  narrower  in  the  small  arteries  than  in  the  corresponding  veins 

(fig.  117). 

In  the  smallest  vessels  it  will  be  found  that  the  elastic  layer  has  dis- 
appeared in  the  veins,  and  the  muscular  tissue  is  considerably  reduced 
in  thickness  in  both  kinds  of  vessels.  Indeed,  it  is  soon  represented 
by  but  a  single  layer  of  contractile  cells,  and  even  these  no  longer 
form  a  complete  layer.  By  this  time  also,  the  outer  coat  and  the 
elastic  layer  of  the  inner  coat  have  entirely  disappeared  both  from 
arteries  and  veins.  The  vessels  are  reduced,  therefore,  to  the  condition 
of  a  tube  formed  of  pavement  epithelium  cells,  with  a  partial  covering 
of  circularly  disposed  muscular  cells. 

Even  in  the  smallest  vessels,  which  are  not  capillaries,  the  differ- 


c     A   b 


cd 


a     b 

/. .  & 


nil  Js^Sl  \\\  m£Zr~~'!  \ 


*'^ 


Fig.  116. — A  small  artery.  A,  with  a  corresponding  vein,  B,  treated  with 
ACETIC  acid.     (,  Magnified  o50  diameters.) 

a,  external  coat  with  elongated  nuclei :  b,  nuclei  of  the  transverse  muscular  tissue  of  the 
middle  coat  <  when  seen  endwise,  a~  at  the  sides  of  the  vessel,  their  outline  is  circular* ; 
c,  nuclei  of  the  epithelium-cells  ;  d,  elastic  layers  of  the  inner  coat. 

ences  between  arteries  and  veins  are  still  manifested.  These  differences 
may  be  enumerated  as  follows  : — The  veins  are  larger  than  the  corre- 
sponding arteries  ;  they  branch  at  less  acute  angles  ;  their  muscular 
cells  are  fewer,  and  their  epithelium-cells  less  elongated  ;  the  elastic 
layer  of  the  inner  coat  is  always  less  marked,  and  sooner  disappears. 

Capillary  vessels. — When  traced  to  their  smallest  branches,  the 
arteries  and  veins  eventually  are  seen  to  be  continued  into  a  network 
of  the  smallest  blood-vessels  or  capillaries.  The  walls  of  these  are 
composed  only  of  flattened  epithelium-cells  (fig.  118)  continuous  with 
those  that  line  the  arteries  and  vein? :  these  cells  can  be  exhibited  by 
staining  a  tissue  with  nitrate  of  silver.  The  capillaries  vary  somewhat 
in  size  and  in  the  closeness  of  their  meshes ;  their  arrangement  in 


94 


THE   ESSENTIALS   OF  HISTOLOGY 


different  parts,  which  is  mainly  determined  by  the  disposition  of  the 
tissue-elements,  may  best  be  studied  when  the  structure  of  the  several 
organs  is  considered. 

In  the  transparent  parts  of  animals,  the  blood  may  be  seen  flowing 
through  the  capillary  network  froni  the  arteries  into  the  veins.     The 


Fig.  117.— A  small  artery,  A,  a»d  vein,  V,  from  the  subcutaneous  connective 

TISSUE   OF   THE    RAT,    TREATED    WITH    NITRATE    OF    SILVER.      (175   diameters.) 

a,  a.  epitheloid  cells  with  b,  h,  their  nuclei :  m,  m,  transverse  markings  due  to  staining  of 
substance  between  the  muscular  fibre-cells;  c,  c,  nuclei  of  connective-tissue  corpuscles 
attached  to  exterior  of  vessel. 

current  is  very  rapid  in  the  small  arteries,  somewhat  less  so  in  the 
veins,  and  comparatively  slow  in  the  capillaries.  The  current  is  fastest 
in  the  centre  of  the  vessel,  slowest  near  the  wall  (inert  layer),  and 
with  care  it  may  be  observed— especially  where  there  is  any  commen- 
cing inflammation  of  the  part,  as  in  the  mesentery  in  consequence  of 


CAPILLARY  BLOOD-VESSELS   AXD   LYMPHATICS 


95 


exposure — that   the    white    blood-corpuscles,   which  always   tend  to 
pass  into  the  inert  layer,  and  to  adhere  occasionally  to  the  inner  sur- 


Fig.  118. — Capillary    Vessels    from 
the    bladder    of    the    cat,    mag- 


The  outlines  of  the  cells  are  stained  by  nitrate 
of  silver. 


Fig.  110. — Capillary  blood- 
vessels IN  THE  AVEB  OF  A 
FROG'S  FOOT,  AS  SEEN  WITH 
THE  MICROSCOPE. 

The  arrows  indicate  the  course  of  the 
blood. 


face  of  the  blood-vessels,  here  and  there  pass  through  the  coats  of  the 
small  vessels,  and  appear  as  migratory  cells  in  the  surrounding 
connective  tissue. 


LYMPHATIC   SYSTEM. 

To  the  lymphatic  system  belong  not  only  the  lymphatic  vessels  and 
lymphatic  glands,  but  also  the  cavities  of  the  serous  membrane*,  which 
are  moistened  with  lymph  and  are  in  open  communication  with  the 
lymphatic  vessels  in  their  parietes. 

The  larger  lymphatic  vessels  somewhat  resemble  the  veins  in 
Structure,  except  that  their  coats  are  much  thinner  and  their  valves 
much  more  numerous.  In  lymphatics  of  somewhat  smaller  size,  the 
wall  of  the  vessel  is  formed,  first,  by  a  lining  of  pavement-epithelium 
cells  (endothelium  of  some  authors),  which  are  elongated  in  the  direc- 
tion of  the  axis  of  the  vessel ;  and,  secondly,  by  a  layer  of  circularly  and 
obliquelv  disposed  muscular  fibres.  In  the  smallest  vessels  (lymphatic 
capillaries),  which,  however,  are  generally  considerably  larger  than 
the  blood-capillaries,  there  is  nothing  but  the  epithelium  remaining, 
and  the  cells  of  this  are  frequently  not  more  elongated  in  one  direction 
than  in  another,  but  have  a  characteristic  wavy  outline  (fig.  121). 

Lymphatics  begin  in  two  ways — either  in  the  form  of  plexuses,  as 
in  membranes  (fig.  120),  or  as  lacunar  interstices,  as  is  the  case  in 
some  of  the  viscera. 


96 


THE  ESSENTIALS  OF  HISTOLOGY 


In  order  to  show  the  lymphatic  vessels,  it  is  generally  necessary  to 
stain  a  tissue  with  nitrate  of  silver ;  but  they  may  easily  be  in- 
jected by  sticking  the  nozzle  of  an  injecting  canula  into  any  tissue 
which  contains  them,  and  forcing  coloured  fluid  under  gentle  pressure 
into  the  interstices  of  the  tissue. 


KTOMW1 


Fig.  120. — Lymphatic  plexus  of  central  tendon  of  diaphragm  of  rabbit, 
pleural  side. 

o,  laxger  vessels  with  lanceolate  cells  and  numerous  valves ;  6,  c,  lymphatic  capillaries  with 
wavy -bordered  cells. 

In  silvered  preparations  it  may  be  observed  that  the  lymphatics 
always  appear  in  the  form  of  clear  channels  in  the  stained  ground-sub- 


LYMPHATIC   VESSELS 


97 


Fig.  1*21. — A  small  part  of  the  lymphatic  plexus  on  the  pleural  surface 
of  the  diaphragm.    (Magnified  110  diameters.)    (Ranvier.) 

L,  lymphatic  vessel  with  characteristic  epithelium;  c,  cell-spaces  of  the  connective  tissue, 
here  and  there  abutting  against  the  lymphatic. 


Fig.  122. — Small  portion  of  peritoneal  surface  of  diaphragm  of  rarp.it,  stained 
with  nituaii    "i    mi.vi'.i:  to  show  the  serous  epithelium. 

I,  lymph-channel  below  the  surface,  lying  between  tendon  bundles,  t,t,  and  over  which  the 
surface-cells  are  seen  to  be  relatively  smaller,  and  to  exhibit  I 
into  the  lymphatic.    The  epithelium  of  the  lymphatic  channel  is  not  represented. 


98  THE   ESSENTIALS   OF  HISTOLOGY 

stance  of  the  connective  tissue,  and  that  their  walls  are  in  close  con- 
nection with  the  cells  and  cell- spaces  of  that  tissue.  But,  except  in 
the  case  of  the  serous  membranes,  there  is  no  open  communication 
between  the  lymphatic  vessels  and  the  interstices  (areola?)  of  the  con- 
nective tissue. 

Development  of  the  blood-vessels  and  lymphatics. — The  blood- 
vessels and  lymphatics  are  developed  in  the  connective  tissue  or  in  the 
mesoblastic  tissue  which  precedes  it,  the  first  vessels  being  formed  in 
the  vascular  area  which  surrounds  the  early  embryo.  Both  kinds  of 
vessels  are  developed  from  cells  | vasoformative  cells)  which  become 
hollowed  out  by  an  accumulation  of  fluid  in  their  protoplasm,  and  in 
the  case  of  developing  blood-vessels  coloured  blood-corpuscles  may  also 
be  formed  within  these  cells  I  see  Development  of  Blood-corpuscles, 
Lesson  II.)  The  cells  branch  and  unite  with  one  another  to  form  a 
network,  and  their  cavities  extend  into  the  branches.  In  the  mean- 
time their  nuclei  multiply  and  become  distributed  along  the  branches, 
cell-areas  being  subsequently  marked  out  around  them.  In  this  way 
intercommunicating  vessels— capillaries  containing  blood  or  lymph — 
are  produced  (fig.    123 j.      These   presently   become   connected  with 


Fig.  123. — Isolated  capillary  network  formed  by  the  junction  ov 
several  hollowed-out  cells,  and  containing  coloured  blood-cor- 
puscles in  a  clear  fluid. 

c,  a  hollow  cell  the  cavity  of  which  does  not  yet  communicate  with  the  network ;  p,  p,  pointed 
cell-processes,  extending  in  different  directions  for  union  with  neighbouring  capillaries. 

previously  formed  vessels,  which  extend  themselves  by  sending  out 
sprouts,  at  first  solid,  and  afterwards  hollowed  out.  It  is  not  precisely 
known  whether  the  larger  blood-vessels  and  lymphatics  are  developed 
at  first  as  capillaries,  the  muscular  and  other  tissues  being  subsequently 
added,  or  whether  they  are  formed  as  clefts  in  the  mesoblastic  tissue 
which  become  bounded  by  flattened  cells. 

The  serous  membranes,  which  may  conveniently  be  studied  in  con- 
nection with  the  lymphatic  system,  are  delicate  membranes  of  connec- 
tive tissue  which  surround  and  line  the  internal  cavities  of  the  body, 
and  are  reflected  over  many  of  the  thoracic  and  abdominal  viscera ;  in 


SEROUS   AND   SYNOVIAL   MEMBRANES  99 

passing  to  which  they  form  folds,  within  which  blood-vessels,  lymphatics, 
and  nerves  pass  to  the  viscera. 

The  inner  surface  is  lined  by  a  continuous  layer  of  pavement- 
epithelium  (fig.  122 1,  which  is  very  distinct  in  nitrate  of  silver  prepa- 
rations. In  some  places  there  are  apertures  in  the  epithelium  which 
lead  direct  into  subjacent  lymphatic  vessels.  These  apertures  are  called 
stomata,  and  are  surrounded  by  small  protoplasmic  cells  ifig.  122,  s,  s). 
They  are  most  numerous  upon  the  peritoneal  surface  of  the  diaphragm, 
but  are  present  in  all  serous  membranes,  and  they  serve  to  prevent  any 
undue  accumulation  of  lymph  within  the  serous  cavity  during  health. 
The  pavement-epithelium  rests  upon  a  homogeneous  basement-mem- 
brane, which  is  especially  well  marked  in  the  serous  membranes  of 
man.  The  rest  of  the  thickness  of  the  membrane  is  composed  of  con- 
nective tissue,  with  a  network  of  fine  elastic  fibres  near  the  inner 
surface. 

The  cavities  of  the  serous  membranes  are  originally  formed  in  the 
embryo  as  a  cleft  in  the  mesoblast  ipleuro-peritoneal  split  i  which 
becomes  lined  with  epithelium,  and  its  wall  eventually  becomes  dif- 
ferentiated into  the  serous  membrane. 

The  synovial  membranes,  which  are  often  compared  with  the 
serous  membranes,  and  are  indeed,  like  the  latter,  connective-tissue 
membranes  which  bound  closed  cavities  moistened  with  fluid,  are  not 
so  intimately  connected  with  the  lymphatic  system,  nor  is  the  fluid 
(synovia)  which  moistens  them  of  the  nature  of  lymph.  Moreover,  it 
is  only  here  and  there  that  there  is  a  lining  of  epithelmm-like  cells,  in 
place  of  the  continuous  lining  of  epithelium  which  we  find  in  the 
serous  membranes.  Curious  villus-like  projections  occur  in  many 
parts  ;  they  are  covered  by  small  rounded  cells,  and  probably  serve  to 
extend  the  surface  for  the  secretion  of  synovia.  The  blood-vessels  of 
synovial  membranes  are  numerous,  and  approach  close  to  the  inner 
surface  of  the  membrane. 


B2 


100  THE   ESSENTIALS   OF  HISTOLOGY 


LESSON   XXII. 

LYMPHATIC   GLANDS,    TONSIL,    THYMUS. 

1.  Sections  of  a  lymphatic  gland  which  has  been  stained  in  bulk  with  magenta 
and  embedded  in  paraffin.1  Notice  (1)  the  fibrous  and  muscular  capsule,  with 
trabecidae  extending  inwards  from  it  through  the  cortex  and  anastomosing  with 
one  another  in  the  medulla,  (2)  the  dense  lymphoid  tissue  (adenoid  tissue  of 
authors)  forming  large  masses  in  the  cortex  (cortical  nodules  I  and  rounded 
cords  in  the  medulla  (medullary  cords).  Notice  also  the  clearer  channel  or 
lymph -sinus  which  everywhere  intervenes  between  the  fibrous  tissue  and  the 
lymphoid  tissue.  Observe  the  fine  fibres  and  branched  cells  which  bridge 
across  this  channel. 

Make  a  general  sketch  under  a  low  power  of  a  portion  of  the  cortex 
together  with  the  adjoining  part  of  the  medulla,  and  under  a  high  power 
drawings  of  small  portions  of  cortex  and  medulla. 

2.  In  sections  of  tonsil  prepared  similarly  to  those  of  the  lymphatic  gland, 
notice  the  large  amount  of  lymphoid  tissue  only  imperfectly  collected  into 
nodules.  Observe  also  that  the  stratified  epithelium,  which  covers  the  mucous 
membrane  here  as  elsewhere  in  the  mouth,  is  infiltrated  with  lymph-cor- 
puscles. Here  and  there  pit-like  recesses  may  be  met  with  glands  opening 
into  the  pits. 

3.  A  similar  preparation  of  the  thymus  gland  of  an  infant.  Notice  that 
the  masses  of  lymphoid  tissue  which  form  the  lobules  of  the  gland  are 
separated  by  septa  of  connective  tissue,  and  that  they  show  a  distinction  into 
two  parts,  cortical  and  medullary.  Observe  the  differences  of  structure  of 
these  two  parts,  and  especially  notice  the  concentric  corpuscles  in  the 
medullary  part. 

Make  a  sketch  of  one  of  the  lobules  under  a  low  power  and  of  a  small  part 
of  the  medulla  under  a  high  power,  including  one  or  two  concentric  corpuscles. 
Measure  the  latter. 


Structure  of  a  lymphatic  gland. — A  lymphatic  gland  is  composed 
of  a,  fibrous  and  muscular  framework,  which  encloses  and  supports  the 
proper  glandular  substance,  but  is  everywhere  separated  from  it  by  a 
narrow  channel,  bridged  across  by  cells  and  fibres,  which  is  known  as 
the  lymph-channel.  The  framework  consists  of  an  envelope  or  capsule 
(fig.  124,  c),  and  of  trabecules  (tr),  which  pass  at  intervals  inwards 
from  the  capsule,  and  after  traversing  the  cortex  of  the  gland  divide 
and  reunite  with  one  another  so  as  to  form  a  network  of  fibrous  bands. 
At  one  part  of  the  gland  there  is  usually  a  depression  (hilus),  and  at 
the  bottom  of  this  the  medulla  comes  to  the  surface  and  its  fibrous 
bands  are  directly  continuous  with  the  capsule. 

1  See  Appendix. 


LYMPHATIC   GLANDS 


101 


Fig.  124. — Diagrammatic  section  of  lymphatic  gland. 

a.  I.  afferent,  e.  I.  efferent  lymphatics  ;  C,  conical  substance ;  M.  reticulating  cords  of  medullary 
sal 'stance  ;  l.s.  lymph-sinus  ;  c,  fibrous  coat  sending  trabecular  tr,  into  the  substance  of  the  gland. 


Fig.  125. — Sectiob  of  the  medullary  substance  of  a  lymphatic  glass  (ox). 

(300  diameter-.  | 

a,  a,  a,  lymphoid  cords  ;  c,  lymph-sinus  ;  6,  6,  trabecule ;  d,  d,  capillary  blood-vessels. 


102 


THE   ESSENTIALS   OF   HISTOLOGY 


The  proper  glandular  substance  (/.  h.)  is  composed  of  lymphoid 
tissue,  i.e.  a  fine  reticulum  with  the  meshes  thickly  occupied  by  lymph- 
corpuscles.  It  occupies  all  the  interstices  of  the  gland,  forming  com- 
paratively large  rounded  masses  in  the  cortex  i  lymphoid  nodules.  G) 
between  the  trabecular  and  smaller  reticulating  cord-like  masses 
(lymphoid  cords.  M)  in  the  medulla. 

The  cells  which  bridge  across  the  lymph-channel  in  the  medulla 
(fig.  125,  c)  are  branching  nucleated  cells  which  often  contain  pigment, 
so  that  this  part  of  the  gland  has  a  dark  colour.  The  lymph-channel 
is  bridged  across  not  only  by  these,  but  also  by  fibres  derived  from  the 
capsule  and  trabecular,  which  pass  to  the  lymphoid  tissue  and  become 
lost  in  its  reticulum.  But  these  fibres  are  often  covered  and  concealed 
by  the  branched  cells. 

Lymphatic  vessels  (fig.  124,  a.  I.)  enter  the  lymph-channels  after 
passing  through  the  capsule,  and  the  lymph  is  conveyed  slowly  along 
the  channels  of  the  cortical  and  medullary  part  towards  the  hilus, 
taking  up  many  lymph-corpuscles  in  its  passage.  At  the  hilus  it  is 
gathered  up  by  an  efferent  vessel  or  vessels  [e.  I.)  which  take  origin  in 
the  lyrnph- sinuses  of  the  medulla. 

An  artery  passes  into  each  gland  at  the  hilus ;  its  branches  are 
conveyed  at  first  along  the  fibrous  cords,  but  soon  pass  into  the 
lymphoid  tissue,  where  they  break  up  into  capillaries  (fig.  125,  d). 
The  blood  is  returned  by  small  veins,  which  are  conducted  along  the 
fibrous  trabecular  to  the  hilus  again. 


Fig.  126. — A  lobule  of  the  thymus  <>f  a  child  as  seen  under  a  low  power. 

c,  cortex  ;  m,  medulla  ;  c,  concentric  corpuscles  ;  6,  blood-vessels  ;  tr,  trabecules. 

The  thymus  gdand  is  a  lymphoid  organ  which  is  found  only  in  the 
embryo  and  during  infancy.  It  is  composed  of  a  number  of  larger  and 
smaller  lobules  (fig.   12(3 1,  which  are  separated  from  one  another  by 


THYMUS   GLAND  103 

septa  of  connective  tissue,  along  which  the  blood-vessels  and  lymphatics 
pass  to  and  from  the  lobules.  Each  lobule  shows  plainly,  when 
examined  with  the  low  power,  a  distinction  into  an  outer  cortical  and 
an  inner  medullary  portion.  The  cortical  part  of  the  lobule  is  imper- 
fectly divided  into  nodules  by  trabecular  of  connective  tissue,  and  is 
very  similar  in  structure  to  the  lymphoid  tissue  of  the  lymphatic 
glands  and  tonsils,  but  the  medulla  is  more  open  in  its  texture,  and 
the  reticulum  is  composed  of  larger,  more  transparent,  flattened  cells, 
and  contains  fewer  lymph-corpuscles.     Moreover,  there  are  found  in 


-;^  « 


Fig.  127. — Elements  of  the  thtmcs.     (300  diameters.)     (Cadiat.) 
a,  lymph-corpuscles  ;   6,  concentric  corpuscle. 

the  medulla  peculiar  concentrically  striated  bodies  (the  concentric  cor- 
puscles, fig.  127),  which  are  usually  composed  of  a  number  of  flattened 
cells  arranged  concentrically  around  one  or  more  central  cells.  Some- 
times these  corpuscles  are  compound,  two  or  three  being  grouped 
together  and  similarly  enclosed  by  flattened  cells.  The  lymphoid 
tissue  is  abundantly  supplied  with  capillary  blood-vessels,  and  large 
lymphatic  vessels  issue  from  the  organ,  but  in  what  way  the  latter  are 
connected  with  the  lobules  has  not  been  ascertained. 

Lymphoid  tissue  occurs  in  many  other  parts  of  the  body  in  addition 
to  the  lymphatic  glands,  tonsils,  and  thymus  gland,  although  it  may 
not,  as  in  these  structures,  constitute  the  bulk  of  the  organ.  Thus  it  is 
found  in  many  mucous  membranes,  such  as  those  of  the  intestine  and 
of  the  respiratory  tract,  both  in  a  diffuse  form  and  also  collected  into 
nodular  masses  which  are  like  the  cortical  nodules  of  a  lymphatic 
gland,  and  may,  like  those,  be  partially  surrounded  by  a  lymph-sinus. 
In  the  spleen  also  a  large  amount  of  lymphoid  tissue  is  found  sheathing 
tin  -mailer  arteries,  and  also  expanded  into  nodular  masses  (Malpighian 
corpuscles  of  the  spleen).  In  these  organs  it  will,  however,  be  studied 
in  subsequent  Lessons. 

Lymphoid  tissue  also  occurs  in  considerable  amount  in  the  serous 
membranes,  especially  in  young  animals  ;  in  the  adult  it  is  often  trans- 
formed into  adipose  tissue.  The  tissue  is  generally  developed  in  con- 
nection with  lymphatic  vessels,  an  accumulation  of  retiform  tissue  and 
lymph-cells  taking  place  either  external  to  and  around  the  lymphatic 


104  THE  ESSENTIALS  OF  HISTOLOGY 

(perilymphatic  nodule) ;  or  the  lymphatic  is  dilated  into  a  sinus  and 


Fig.  128. — Developing  lymphatic  nodules,  from  the  omentum  of  a  guinea- 
pig. 

A,  perilymphatic  nodule ;  a,  lymphatic  vessel ;  c,  part  of  its  epithelial  wall,  seen  in  optical 
section  ;  e,  lymph-corpuscles  within  the  vessel ;  b,  lymphoid  tissue  of  the  nodule  ;  d,  blood- 
capillaries  ;  *B,  endolymphatic  nodule ;  a,  vein  ;  6,  artery  ;  c,  capillaries  ;  d,  a  lymphatic 
vessel,  in  which  this  whole  system  of  blood-vessels  is  enclosed  ;  e,  lymphoid  tissue  within 
the  lymphatic  vessel ;  /,  wall  of  the  lymphatic  in  optical  section. 

the  formation   of  lymphoid   tissue   occurs   within  it   (endolymphatic 
nodule)  (see  fig.  128). 


105 


LESSON   XXIII. 

THE   SKIN. 

1.  Sections  of  skin  from  the  palmar  surface  of  the  fingers.  The  sections 
are  to  be  made  vertical  to  the  surface,  and  should  extend  down  as  far  as  the 
subcutaneous  tissue.  They  may  be  stained  with  logwood  or  picro-carmme 
and  mounted  in  Canada  balsam.  In  these  sections  notice  the  layers  of  the 
epidermis  and  their  different  behaviour  to  the  staining  fluid.  Notice  also  the 
papillae  projecting  from  the  coriuin  into  the  epidermis,  and  look  for  tactile 
corpuscles  within  them.  In  very  thin  parts  of  the  sections  the  fine  inter- 
cellular channels  in  the  deeper  parts  of  the  epithelium  (see  Lesson  VI.  p.  22) 
may  be  seen  with  a  high  power.  The  convoluted  tubes  of  the  sweat-glands 
will  be  seen  here  and  there  in  the  deeper  jiarts  of  the  corium,  and  in  thick 
sections  the  corkscrew-like  channels  by  which  the  sweat  is  conducted  through 
the  epidermis  may  also  be  observed.  Make  a  sketch  showing  the  general 
structure  tmder  a  low  power,  and  other  sketches  to  exhibit  the  most  important 
details  under  a  high  power.  Measure  the  thickness  of  the  epidermis  and  the 
length  of  the  papillae. 

2.  Sections  of  the  skin  of  the  scalp,  vertical  to  the  surface  and  parallel  to 
the  slope  of  the  hair-follicles,  and  others  parallel  to  the  surface,  and  therefore 
across  the  hair-follicles.  Stain  and  mount  in  the  same  way  as  in  the  last 
preparation.     Examine  also  the  structure  of  the  hairs. 

In  these  preparations  the  details  of  structure  of  the  hairs  and  hair-follicles 
together  with  the  sebaceous  glands  and  the  little  muscles  of  the  hair-follicles 
are  to  be  made  out. 

3.  Vertical  sections  across  the  nail  and  nail-bed,  cut  with  a  strong 
scalpel  or  razor.  The  sections  are  stained  with  hematoxylin  or  picro-cannine. 
Notice  the  ridges  (not  papillae)  of  the  corium  projecting  into  the  epidermis. 
Observe  also  the  distinction  of  the  epidermis  into  Malpighian  layer  and  nail 
proper. 

4.  Mount  in  Canada  balsam  a  section  from  a  portion  of  skin  of  which  the 
blood-vessels  have  been  injected,  and  notice  the  distribution  of  the  capillaries 
to  the  sweat-glands,  to  the  hair-follicles,  and  to  the  papillary  surface  of  the 
corium. 


The  skin  is  composed  of  two  parts,  epidermis  and  cutis  vera. 

The  epidermis,  or  scarf  skin,  is  a  stratified  epithelium  (fig.  120). 
It  is  composed  of  a  number  of  layers  of  cells,  the  deeper  of  which  are 
soft  and  protoplasmic,  and  form  the  rete  mucosum  of  Malpighi,  whilst 
the  superficial  layers  are  hard  and  horny  ;  this  horny  portion  some- 
times constituting  the  greater  part  of  the  thickness  of  the  epidermis. 
The  deepest  cells  of  the  rctc  mucosum.  which  are  set  on  the  surface  of 
the  cutis  vera,  are  columnar  (fig.  129,  c)  in  shape.     In  the  coloured 


106 


THE   ESSENTIALS  OF  HISTOLOGY 


races  of  mankind  these  cells  contain  pigment-granules.  In  the  layers 
immediately  above  them  the  cells  are  polyhedral  (fig.  129,  p).  Between 
all  these  cells  of  the  rete  mucosum  there  are  fine  intercellular  clefts 
which  separate  the  cells  from  one  another,  but  are  bridged  across  by 
fine  fibres,  which  pass  from  ceU  to  cell.  The  intercellular  channels 
serve  for  the  passage  of  lymph,  and  within  them  occasional  lymph- 
corpuscles  may  be  found,  often  having  a  stellate  figure  from  compres- 
sion. The  most  superficial  layer  of  the  rete  mucosum  is  formed  of 
somewhat  flattened  granular  cells  [stratum  granulosum,  S.gr).     Im- 


MJ 


'  /.','  ■■: 


■'&\ 


rw 


n 
Fig.  129. — Section  of  epidermis. 

H,  horny  layer,  consisting  of  s,  superficial  horny  scales  ;  sir,  swollen-out  horny  cells ;  s.l. 
stratum  lucidum ;  M,  rete  mucosum  or  Malpighian  layer,  consisting  of  p,  prickle-cells, 
several  rows  deep  :  c,  elongated  cells  forming  a  >ingle  stratum  near  the  corium  :  and  t.gr. 
stratum  granulosum  of  Langerhans,  just  below  the  stratum  lucidum  ;  n,  part  of  a  plexus 
of  nerve-fibres  in  the  superficial  layer  of  the  cutis  vera.  From  this  plexus  fine  varicose 
nerve-fibrils  may  be  traced  passing  up  between  the  epithelium-cells  of  the  Malpighian 
layer. 

mediately  above  this  layer,  the  horny  part  of  the  epidermis  commences, 
as  a  layer  of  clear  compressed  cells  several  deep  (stratum  lucidum,  s.l.). 
Above  this  comes  the  main  part  of  the  horny  layer.  It  is  composed  of 
a  number  of  layers  of  somewhat  swollen  cells  (sit).),  the  nuclei  of 
which  are  no  longer  visible.  These  cells  become  flatter  as  they 
approach  the  surface,  where  they  eventually  become  detached  in  the 
form  of  thin  horny  scales  (s). 

The  growth  of  the  epidermis  takes  place  by  a  multiplication  of  the 


THE   SKIN 


107 


cells  of  the  deeper  layers.  The  newly  formed  cells,  as  they  grow,  push 
towards  the  surface  those  which  were  previously  formed,  and  in  then- 
progress  the  latter  undergo  a  chemical  transformation,  which  converts 
their  protoplasm  into  horny  material.  This  change  seems  to  occur 
at  the  stratum  granulosum  (see  fig.  130)  ;  the  granules  which  occupy 
the  cells  of  that  layer  being  composed  of  a  substance  termed  eleidin, 
which  is  transformed  into  keratin. 

No  blood-vessels  pass  into  the  epidermis,  but  it  receives  nerves 
which  ramify  between  the  cells  of  the  rete  mucosiun  in  the  form  of 
fine  varicose  fibrils  (fig.  129).  , 


W^e 


Fig.  130. — Portion  <>i    epidermis  from  a  section  of  the  skin  of  the 

FINGER,   COLOURED   WITH    PICROCARMINATE   OF   AMMONIA.    (Kanvier.) 

a,  stratum  corneum ;  6,  stratum  lucMum  with  diffused  flakes  of  eleidin  ;  c,  stratum  grauu- 
losum,  the  cells  tilled  with  drops  of  eleidin;  d,  prickle-cells;  e,  dentate  projections  by 
which  the  deepest  cells  of  the  epidermis  are  fixed  to  the  cutis  vera. 


The  cutis  vera  or  corium  is  composed  of  dense  connective  tissue, 
which  becomes  more  open  and  reticular  in  its  texture  in  its  deeper 
part,  where  it  merges  into  the  subcutaneous  tissue.  The  superficial  or 
vascular  layer  of  the  corium  bears  minute  papilla,  which  project  up 
into  the  epidermis,  which  is  moulded  over  them.  These  papillae  for 
the  most  part  contain  looped  capillary  vessels  (fig.  137),  but  some, 
especially  those  of  the  palmar  surface  of  the  hand  and  fingers,  and  the 
corresponding  part  of  the  foot,  contain  tactile  corpuscles,  to  which 
medullated  nerve-fibres  pass  (fig.  97,  b). 

In  some  parts  of  the  body  (scrotum,  penis,  nipple,  and  areola), 
involuntary  muscular  tissue  occurs  in  the  deeper  portions  of  the  cutis 
vera,  and  in  addition,  wherever  hairs  occur,  small  bundles  of  this 
tissue  are  attached  to  the  hair-follicles. 

The  blood-vessels  of  the  skin  are  distributed  almost  entirely  to  the 
surface,  where  they  form  a  close  capillary  network,  sending  up  loops 


108 


THE   ESSENTIALS   OF   HISTOLOGY 


into  the  papillae.  Special  branches  are  also  distributed  to  the  various 
appendages  of  the  skin,  viz.  the  sweat-glands  and  hair-follicles,  with 
their  sebaceous  glands  and  little  muscles,  as  well  as  to  the  little  masses 
of  adipose  tissue  which  may  be  found  in  the  deeper  parts  of  the  cutis. 

The  lymphatics  originate  near  the  surface  in  a  network  of  vessels, 
which  is  placed  a  little  deeper  than  the  blood-capillary  network.  They 
receive  branches  from  the  papilla?,  and  pass  into  larger  vessels,  which 
are  valved.  and  which  run  in  the  deeper  or  reticular  part  of  the  corium. 
From  these  the  lymph  is  carried  away  by  still  larger  vessels,  which 
course  in  the  subcutaneous  tissue. 

The  appendages  of  the  skin  are  the  nails,  the  hairs,  with  their 
sebaceous  glands  and  the  sweat-glands.  They  are  all  developed 
as  thickenings  and  downgrowths  of  the  Malpighian  laver  of  the  epi- 
dermis. 


Fig.  131. — Section  across  the  nail  and  nail-bed.     (100  diameters.) 

(Heitzmann.) 

P,  ridges  with  blood-vessels  ;  B,  rete  mucosum  ;  N,  nail. 

The  nails  are  thickenings  of  the  stratum  lucidum  of  the  epidermis, 
which  are  developed  over  a  specially  modified  portion  of  the  corium, 
which  is  known  as  the  bed  of  the  nail,  the  depression  at  the  posterior 
part  of  the  nail-bed  from  which  the  root  of  the  nail  grows  being 
known  as  the  nail-groove.  The  distal  part  of  the  nail  forms  the  free 
border,  and  is  the  thickest  part  of  the  body  of  the  nail.  The  horny 
substance  of  the  nail  (fig.  131,  N)  is  composed  of  clear  horny  cells, 
each  containing  the  remains  of  a  nucleus  ;  it  rests  immediately  upon 
a  Malpighian  layer  (B)  similar  to  that  which  is  found  in  the  epidermis 


THE   SKIN  109 

generally.  The  coriurn  of  the  nail-bed  is  beset  with  longitudinal 
ridges  instead  of  the  papillae  which  are  present  over  the  rest  of  the 
skin  ;  these,  like  the  rest  of  the  superficial  part  of  the  corium,  are 
extremely  vascular.  The  nails  are  developed  in  the  foetus  at  about 
the  third  month,  the  groove  being  formed  at  this  time  in  the  corium, 
and  the  nail-rudiment  appearing  in  it  as  a  thickening  of  the  stratum 
lucidum,  which  extends  forward  over  the  bed.  It  becomes  free  in  the 
sixth  month,  its  free  end  being  at  first  thin,  but  as  it  grows  forward 
over  the  bed  it  appears  to  receive  additions  on  its  under  surface,  so 
that  after  a  time  the  distal  part  becomes  the  thicker.  The  superficial 
layers  of  the  cuticle  which  originally  covered  the  developing  nail  become 
detached,  and,  after  birth,  only  remain  as  the  narrow  border  of  cuticle 
which  overlies  the  lunula. 

The  hairs  are  growths  of  the  epidermis,  which  are  developed  in 
little  pits — the  hair-follicle* — which  extend  downwards  into  the  deeper 
part  of  the  corium,  or  even  into  the  subcutaneous  tissue.  The  hair 
grows  from  the  bottom  of  the  follicle,  the  part  which  thus  lies  within 
the  follicle  being  known  as  the  root. 

The  substance  of  a  hair  is  mainly  composed  of  a  pigmented,  horny, 
fibrous  material  (fig.  132,/),  which  can  be  separated  by  the  action 
of  sulphuric  acid  into  long  tapering  cells,  the  nuclei  of  which  are 
still  visible.  This  fibrous  substance  of  the  hair  is  covered  by  a  layer 
of  delicate  imbricated  scales  termed  the  ha ir-cuticle  I  c ) .  In  many  hairs, 
but  not  in  all,  the  centre  is  occupied  by  a  dark-looking  axial  substance 
( medulla,  m),  formed  of  angular  cells  which  contain  granules  of  eleidin, 
particles  of  dark  pigment,  and  frequently  minute  air-bubbles.  The 
latter  may  also  occur  in  interstices  in  the  fibrous  substance.  When 
they  are  present,  the  hair  looks  white  by  reflected  light.  The  root  has 
the  same  structure  as  the  body  of  the  hair,  except  at  its  extremity, 
which  is  enlarged  into  a  knob  (fig.  133,  b)  ;  this  is  composed  mainly 
of  soft,  growing  cells,  and  fits  over  a  vascular  papilla  (p),  which  pro- 
jects up  into  the  bottom  of  the  follicle.  The  follicle,  like  the  skin 
itself,  of  which  it  is  a  recess,  is  composed  of  two  parts  :  one  epithelial, 
and  the  other  connective  tissue.  The  epithelial  or  epidermic  part  of 
the  follicle  closely  invests  the  hair-root,  and  is  often  in  great  part 
dragged  out  with  it ;  hence  it  is  known  as  the  root-sheath.  It  consists 
of  an  outer  layer  of  soft  columnar  and  polyhedral  cells,  like  the  Mal- 
pighian  layer  of  the  epidermis — the  outer  root-sheath  (figs.  133,/; 
L84,  e)  :  and  of  an  inner,  thinner,  horny  stratum  next  the  hair — the 
inner  root-sheath  (figs.  133,  g  ;  134,/).  The  inner  root-sheath  itself 
consists  of  three  layers,  the  outermost  being  composed  of  oblong  cells 
without  nuclei  iHenle's  layer),  the  next  of  flattened  polyhedral  nu- 
cleated cells  [Huxley's  layer),  and  the  third — the  cuticle  of  the  root- 
sheath — being  a  thin  layer  of  downwardly  imbricated  scales,  which  fit 
over  the  upwardly  imbricated  scales  of  the  hair  itself. 

The  connective  tissue  or  dermic  part  of  the  hair-follicle  (fig.  134, 
a,  c,  d)  is  composed  internally  of  a  vascular  layer,  separated  from  the 


110 


THE  ESSENTIALS  OF  HISTOLOGY 


Fig.   132.— Piece    of    human 
hair.     (Magnified.) 

A,  seen  from,  the  surface ;  B,  in 
optical  section,  c,  cuticle ;  /, 
fibrous  substance :  m,  medulla, 
the  air  having  been  expelled'by 
Canada  balsam. 


Fig.  134.— Section  <>f  hair- 

FOLLIlLK. 

I,  dermic  coat  of  follicle ;  2,  epi- 
dermic  coat  or  root-sheath  :  ". 
outer  layer  of  dermic  coat,  with 
blood-vessels,  b.  l.  cut  acn 
middle  layer  :  d.  inner  or  hyaline 
layer;  e,  outer  root-sheath;  /,  u, 
inner  root-sheatb  :  ft,  cuticle  of 
root -sheath  ;  I,  hair. 


Fig.  133. — Hair-follicle  in  longitudinal 

SECTION. 

a,  mouth  of  follicle  :  h.  neck  ;  c.  hulb  :  d.  e,  dermic 
:  /.  outer  root-sheath  ;  ;/,  inner  root -sheath  ; 
ft,  hair;  /.,  its  medulla  ;  I,  hair-knob  ;  »i,  w 
tissue;  ».  hair-muscle:  o.  papilla  of  skin:  p, 
papilla  of  hair  :  s,  rete  mucosum, continuous  with 
outer  root-sheath  ;  ep,  horny  layer  ;  /,  sebaceous 
gland. 


THE   SKIN 


111 


root-sheath  by  a  basement -membrane  termed  the 
follicle.  This  inner  vascular  layer  corresponds  to 
of  the  cutis  vera.  Its  fibres  and  cells  have  a 
regular  circular  arrangement  around  the  follicle, 
the  cells  being  flattened  against  the  hyaline  layer. 
Externally  the  dermic  coat  of  the  follicle  has 
a  more  open  texture,  corresponding  to  the  reti- 
cular part  of  the  cutis,  and  containing  the  larger 
branches  of  the  arteries  and  veins.  In  the  large 
tactile  hairs  of  animals,  the  veins  near  the  bottom 
of  the  follicle  are  dilated  into  sinuses,  so  as  to  pro- 
duce a  kind  of  erectile  structure. 

The  hair  grows  from  the  bottom  of  the  follicle 
by  multiplication  of  the  soft  cells  which  cover  the 
papilla,  these  cells  becoming  elongated  to  form  the 
fibres  of  the  fibrous  substance,  and  otherwise  modi- 
fied to  produce  the  medulla  and  cuticle. 

When  a  hair  is  eradicated,  a  new  hair  is  pro- 
duced from  these  cells.  It  is  not  uncommon  to  find 
hair-follicles  in  which  the  whole  of  the  lower  part 
has  degenerated  in  such  a  way  that  the  vascular 
papilla,  and  the  soft,  growing  cells  which  cover  it, 
may  have  entirely  disappeared.  The  hair  then 
ceases  to  grow,  and  eventually  becomes  lost,  but 
its  place  may  be  again  supplied  by  a  new  hair, 
which  becomes  formed  in  a  downgrowth  from 
either  the  bottom  or  the  side  of  the  hair-follicle,  a 
new  papilla  first  becoming  formed  at  the  extremity 
of  the  downgrowth  ifig.  135 1.  If  not  previously 
detached,  the  old  hair  may  be  pushed  from  out  the 
follicle  by  the  one  which  replaces  it. 

The  hairs  are  originally  developed  in  the  embryo 
in  the  form  of  small  solid  down  growths  from  the 
Malpighian  layer  of  the  epidermis  (fig.  180,  A). 
The  hair-rudiment,  as  it  is  called,  is  at  first  com- 
1  entirely  of  soft,  growing  cells  ;  but  presently 
those  in  the  centre  become  differentiated,  so  as  to 
produce  a  minute  hair  invested  by  inner  root- 
th,  and  its  base  resting  upon  a  papilla  which 
ha-  grown  up  into  the  extremity  of  the  hair-rudi- 
ni. m  from  the  corium  (fig.  13G,  Bi.  As  the 
minute  hair  grows,  it  pushes  its  way  through  the 
superficial  layers  of  the  epidermis,  which  it  finally 
perforates  (Cj.  The  hair-rudiments  commence  at 
the  third  or  fourth  month  of  fatal  life  :  their 
growth  is  completed  about  the  fifth  or  sixth 
month,  and  they  form  a  complete  hairy  covering 


hyaline  layer  of  the 
the  superficial  layer 


I"l'..  135. — COMMEK- 
(  IVi,  Bl  I'l.A'  I  Ml  NT 
OF  OLD  BV  SEW 
HAIB.      (Toldt.) 

o,  out  ith;   b. 

den:  Hide : 

/,  downgrowth  of  epi- 
thelium ;..  form  ii''A 
hair-follicle :  ;•.  papilla 
of  new  hair  commen- 
cing :  I  hair; 
t.  .-eous 
gland. 


112 


THE   ESSENTIALS   OF  HISTOLOGY 


termed  the  lanugo.  This  is  entirely  shed  within  a  few  months  of  birth, 
the  new  hairs  being  formed  in  downgrowths  from  the  old  hair-follicles 
in  the  manner  already  mentioned. 

Hairs  grow  at  the  rate  of  half  an  inch  per  month.  They  are  found 
all  over  the  body  except  on  the  palms  of  the  hands  and  the  soles  of 
the  feet,  and  on  the  distal  phalanges  of  the  fingers  and  toes.     They 


Fig.  136. 

Hair-rudiment  from  an  embryo  of  six  weeks.  «.  horny,  and  6,  mucous  or  Malpighian 
layer  of  cuticle  :  i,  basement-membrane  ;  m,  cells,  some  of  which  are  assuming  an  oblong 
figure,  which  chiefly  form  the  future  hair.  B.  Hair-rudiment,  with  the  young  hair  formed 
but  not  yet  risen  through  the  cuticle,  a,  horny,  6.  Malpighian  layer  of  epidermis  ;  c,  outer, 
d,  inner,  root-sheath  ;  e,  hair-knob :  /,  stem,  and  </.  point  of  the  hair ;  h,  hair-papilla ; 
n,  n,  commencing  sebaceous  follicles.    C.  Hair-follicle  with  the  hair  just  protruded. 


usually  slant,  and  in  the  negro  the  hair-follicles  are  even  considerably 
curved.  On  the  sc*alp  they  are  set  in  groups,  as  is  well  seen  in  a  hori- 
zontal section. 

The  hairs  of  animals  are  often  curiously  marked  by  the  arrange- 
ment of  their  medulla,  the  markings  being  often  characteristic  of  the 
particular  species. 

Muscles  of  the  hairs. — A  bundle  of  plain  muscular  tissue  is  attached 
to  each  hair-follicle  ;  passing  from  the  superficial  part  of  the  corium,  on 
the  side  to  which  the  hair  slopes,  obliquely  downwards,  to  be  attached 
near  the  bottom  of  the  follicle  (arrector  pili,  fig.  133,  n).  When  the 
muscle  contracts,  the  hair  becomes  erected,  and  the  follicle  is  dragged 
upwards  so  as  to  cause  a  prominence  on  the  general  surface  of  the 
skin  ;  whilst  the  part  of  the  corium  from  which  the  little  muscle  arises 
is  correspondingly  depressed ;  the  roughened  condition  known  as 
'  goose  skin '  being  in  this  way  produced. 

The  sebaceous  glands  (fig.  133,  t)  are  small  saccular  glands,  the 


THE   SKIN 


113 


ducts  from  which  open  into  the  mouths  of  the  hair-follicles.  Both  the 
duct  and  the  saccules  are  lined  by  epithelium,  which  becomes  charged 
with  fatty  matter.  This  sebaceous  matter  is  discharged  into  the  cavity 
of  the  saccule,  probably  owing  to  the  disintegration  of  the  cells  within 
which  it  is  formed.  There  may  be  two  or  more  sebaceous  glands 
attached  to  each  follicle. 

The  sebaceous  glands  are  developed  as  outgrowths  from  the  outer 
root-sheath. 

The  sweat-glands  are  abundant  over  the  whole  skin,  but  they  are 
most  numerous  on  the  palm  of  the  hand  and  on  the  sole  of  the  foot. 
They  are  composed  of  coiled  tubes,  which  lie  in  the  deeper  part  of  the 
integument  and  send  their  ducts  up  through  the  cutis  to  open  on  the 
surface  by  corkscrew-like  channels  which  pierce  the  epidermis  (fig.  137j. 


Fig.  137. — Duct  of  a  sweat-gland  passing  through  the  epidermis. 
(Magnified  200  diameters.)     (Heitzmann.) 

BP,  papilla;  with  blood-vessels  injected  ;  V.  rete  mucosum  between  the  papillae  ;  E,  stratum 
corneum  ;  PL,  stratum  granulosum  ;  D,  duct,  opening  on  the  surface  at  P. 


The  glandular  or  secreting  tube  is  a  convoluted  tube  composed  of 
a  basement-membrane  lined  by  a  single  layer  of  cubical  or  columnar 
epithelium-cells,  and  with  a  layer  of  longitudinally  disposed  plain 
muscular  fibres  between  the  epithelium  and  basement-membrane. 
It  is  considerably  larger  than  the  efferent  tube  or  duct,  which  begins 
within  the  gland  and  usually  makes  several  convolutions  before  leaving 
this  to  traverse  the  cutis  vera.  The  efferent  tube  has  an  epithelium 
consisting  of  two  or  three  layers  of  cells,  within  which  is  a  well- 
marked  cuticular  lining,  but  there  is  no  muscular  layer.  The  passage 
through  the  epidermis  has  no  proper  wall,  but  is  merely  a  channel 
excavated  between  the  epithelium-cells. 

The  cerummous  glands  of  the  ear  are  modified  sweat- "lands. 


114 


THE   ESSENTIALS   OF  HISTOLOGY 


The  sweat-glands  are  developed,  like  the  hairs,  from  downgrowths 
of  the  Malpighian  layer  of  the  epidermis  into  the  corium,  the  rudi- 


Fig.  138. — Section  of  a  sweat-gland  in  the  skin  of  man. 

a,  a,  secreting  tubes  in  section  ;  6,  a  tube  seen  from  above  ;  c,  c,  efferent  tubes  ;  d,  inter- 
tubular  connective  tissue  with  blood-vessels.  1,  basement  membrane ;  2,  muscular 
fibres  cut  across  ;  3,  secreting  epithelium  of  a  tubule. 


ments  which  are  thus  formed  becoming  eventually  coiled  up  at  their 
extremities  and  converted  into  hollow  tubes. 

The  sweat-glands  receive  nerve-fibres,  and  each  gland  has  a  special 
cluster  of  capillary  blood-vessels. 


115 


LESSON   XXIV. 

STRUCTURE  OF  THE   HEART. 

1.  In  a  section  through  the  wall  of  the  auricle  which  has  been  stained  with 
inagenta  and  mounted  in  glycerine,  notice  the  relative  thickness  of  the 
epioardium,  myocardium,  and  endocardium.  Observe  the  blood-vessels  and 
nerve-fibres  under  the  epicardium.  often  embedded  in  fat ;  here  and  there  a 
ganglion  may  be  seen  under  this  membrane.  Notice  also  the  elastic  networks 
under  both  the  pericardium  and  endocardium.  Make  a  general  sketch  from 
this  section. 

2.  Section  through  the  wall  of  the  ventricle,  stained  with  logwood  and 
mounted  in  Canada  balsam.  The  muscular  fibres  are  variously  cut.  In 
those  cut  longitudinally,  notice  the  branching  of  the  fibres  and  their  union 
into  a  network.  Notice  also  that  although  the  fibres  are  cross-striated  this  is 
less  distinct  than  in  voluntary  muscle,  and  the  nuclei  lie  in  the  centre  of  each 
fibre.  Transverse  markings  may  also  be  seen  passing  across  the  fibres 
between  the  nuclei  and  indicating  a  division  into  cells.  The  endocardium  is 
very  thin,  especially  over  the  columnae  carneae. 

3.  The  lymphatics  of  the  heart  are  easily  injected  with  Berlin  blue  by- 
sticking  the  nozzle  of  the  injecting  syringe  into  the  muscular  substance,  in 
the  interstices  of  which  the  lymphatics  arise.  These  commencing  lymphatics 
lead  to  efferent  vessels  which  pass  to  the  base  of  the  heart  under  the  epi- 
cardium. 

4.  Section  through  one  of  the  valves  of  the  heart,  stained  and  mounted 
as  preparation  2. 

5.  The  epithelium  which  covers  the  epicardium,  and  that  which  lines  the 
endocardium,  may  be  studied  in  preparations  of  the  fresh  organ  which  have 
been  treated  with  nitrate  of  silver  and  subsequently  exposed  to  the  light  and 
hardened  in  alcohol. 


The  muscular  substance  of  the  heart  {myocardium)  is  composed  of 
transversely  striated  muscular  fibres  (fig.  139),  which  differ  from  those 
of  voluntary  muscle  in  the  following  particulars  :  their  striations  are 
less  distinct ;  they  have  no  sarcolemma  ;  they  branch  and  unite  with 
neighbouring  fibres,  and  their  nuclei  lie  in  the  centre  of  the  fibres. 
Moreover,  the  fibres  are  composed  of  a  series  of  short  cylindrical  cells 
(fig.  140)  joined  together  end  to  end,  each  corresponding  to  one  of  the 
nuclei.  The  lines  of  junction  of  these  cells  may  sometimes  be  seen  in 
longitudinal  sections  stained  with  hematoxylin  or  magenta  ;  but  they 
come  much  more  distinctly  into  view  in  sections  of  the  fresh  tissue 
stained  with  nitrate  of  silver. 

i2 


116 


THE  ESSENTIALS  OF  HISTOLOGY 


In  the  interstices  of  the  muscular  tissue  there  is  a  little  areolar 
tissue  in  which  run  the  very  numerous  blood-capillaries  and  the 
lacunar  lymphatics. 


Fig.  139. — Muscular  fibres  from  the 
heart,  magnified,  showing  their 
cross-stri.e,  division's,  and  junc- 
TIONS. 

The  nuclei  and  cell-junctions  are  only  repre- 
sented on  the  right-hand  side  of  the  figure. 


Fig.  140. — Six  muscular  fibre-cells 
fro.m  the  heart.  (Magnified  425 
diameters.) 

a,  line  of  junction  between  two  cells ;  b,  c, 
branching  of  cells. 


-$ 


Fig.  141. — Section  of  the  epicardium  of  the  right  auricle. 

O,  serous  epithelium  in  section :  6,  conneetive-tis>ue  layer  ;  c,  elastic  network  :  d,  subserous 
areolar  tissue ;  e,  fat ;  /,  section  of  a  blood-vessel  ;  ■/.  a  small  ganglion :  h,  muscular 
fibres  of  the  myocardium  ;  i,  intermuscular  areolar  tissue. 


The  myocardium  is  covered  externally  by  a  layer  of  serous  mem- 
brane— the  epicardium  (cardiac  pericardium,  fig.  141) — composed,  like 
other  serous  membranes,  of  connective  tissue  and  elastic  fibres,  the 


STRUCTURE   OF  THE   HEART 


117 


latter  being  most  numerous  in  its  deeper  parts.  Underneath  the 
epicardium  run  the  blood-vessels,  nerves,  and  lymphatic  vessels  of  the 
heart,  embedded  in  areolar  and  adipose  tissue ;  this  tissue  being  con- 
tinuous with  that  which  lies  between  the  muscular  bundles. 

The  endocardium  (fig.  142)  has  a  structure  not  very  unlike  the 
pericardium.  It  is  lined  by  a  pavement -epithelium,  like  the  epithelium 
of  a  serous  membrane,  and  consists  of  connective  tissue  with  elastic 
fibres  in  its  deeper  part,  between  which  there  may,  in  some  parts,  be 


Fig.  142. — Section  of  the  endocar- 
dium  OF   THE   EIGHT   AURICLE. 

a,  lining  epithelium  ;  b,  connective  tissue  with 
fine  elastic  fibres ;  c,  layer  with  coarser 
elastic  fibres  :  J  sub-endocardial  connective 
tissue  continuous  with  the  intermuscular 
tissue  of  the  myocardium  ;  A,  muscular 
fibres  of  the  myocardium  :  m,  plain  muscu- 
lar tissue  in  the  endocardium. 


Fig.  143. — Section  through  oxe  of 
the  flaps  of  the  aortic  valve, 
and  part  <>i  the  corresponding 
six!  s  oi    Valsalva,  with  the  ad- 

JOINING  PART  OK  THE  VENTElCUbAR 
WALL. 

a,  endocardium,  prolonged  over  the  valve;  b, 
Bnb-endocardial  tissue  ;  e,  fibrous  tissue  of 
the  valve,  thickened  at  e'  near  the  free  edge  ; 

"'.   tion  of  the  lunula;  e,  section  of  the 

fihrou-  ring  ;  /',  muscular  fibres  of  the  ven- 
tricle attached  to  it ;  g,  loose  areolar  tissue 
at  the  base  of  the  ventricle  ;  s.  I',  sinus 
Valsilvie;  1,  2,  3,  inner,  middle,  and  outer 
coat-  of  the  aorta. 


■ 


found  a  few  plain  muscular  fibres.  Fat  is  sometimes  met  with  under 
the  endocardium. 

In  some  animals,  e.g.  the  sheep,  and  sometimes  also  in  man,  large 
beaded  fibres  are  found  under  the  endocardium.  These  are  formed  of 
large  clear  cells  joined  end  to  end,  and  generally  containing  in  their 
centre  two  nuclei,  whilst  the  peripheral  part  of  the  cell  is  formed  of  cross- 
striated  muscular  tissue  ;  they  are  known  as  the  fibres  of  Purkinje. 

The  valves  of  the  heart  are  formed  of  folds  of  the  endocardium 
strengthened  by  fibrous  tissue  (fig.  113).    This  tissue  forms  a  thicken- 


118  THE   ESSENTIALS  OF   HISTOLOGY 

ing  near  the  free  edge  of  the  valve  {&).  At  the  base  of  the  auriculo- 
ventricular  valves  a  little  of  the  muscular  tissue  of  the  auricle  may  be 
found  passing  a  short  distance  into  the  valve. 

The  nerves  of  the  heart  are  seen  in  sections  underneath  the  epi- 
cardium  of  both  auricles  and  ventricles ;  in  the  former  situation,  they 
are  connected  at  intervals  with  small  ganglia  (fig.  141,  g).  Their 
branches  pass  to  the  muscular  substance,  but  their  mode  of  termina- 
tion has  not  been  ascertained. 


119 


LESSON  XXV. 

THE   TRACHEA   AXD   LUNGS. 

1.  In  sections  of  trachea,  stained  with  logwood  or  borax-carmine,  and  mounted 
in  Canada  balsam,  notice  the  ciliated  epithelium,  the  basement-membrane 
lie  thickness  in  the  human  tracheal,  the  lymphoid  tissue  of  the  mucous 
membrane,  the  elastic  tissue  external  to  this,  and  lastly  the  fibrous  membrane 
containing  the  cartilages.  In  the  mucous  membrane  and  submucous  areolar 
tissue  look  for  sections  of  mucous  glands,  ducts  of  which  may  be  seen  opening 
on  the  surface.  At  the  back  of  the  trachea  notice  the  plain  muscular  fibres 
transversely  arranged ;  there  may  be  larger  mucous  glands  external  to  these. 

2.  In  sections  of  lung  similarly  prepared,  notice  the  sections  of  the  alveoli 
collected  into  groups  (infundibula).  Find  sections  of  bronchial  tubes, 
some  cut  longitudinally  and  passing  at  their  extremities  into  the  infundibula, 
others  cut  across  ;  the  latter  show  the  structure  of  the  tubes  best.  In  each 
tube  notice  the  ciliated  epithelium  internally.  Next  to  this  the  mucous 
membrane  containing  numerous  elastic  fibres  and  often  thrown  into  folds  ; 
then  the  layer  of  circular  muscular  fibres,  and  outside  this,  loose  fibrous  tissue 
in  which  in  larger  bronchial  tubes  the  pieces  of  cartilage  may  be  seen  embedded. 
Small  mucous  glands  may  also  be  observed  in  the  fibrous  tissue  sending  their 
ducts  through  the  other  layers  to  open  on  the  inner  surface.  Notice  always 
accompanying  a  section  of  a  bronchial  tube  the  section  of  a  branch  of  the 
pulmonary  artery. 

In  the  sections  of  the  alveoli  observe  the  capillary  vessels  passing  from 
one  side  to  the  other  of  the  intervening  septa  ;  and  in  places  where  the  thin 
wall  of  an  alveolus  is  to  be  seen  in  the  section,  try  and  make  out  the  net- 
work of  blood-capillaries  upon  it.  Notice  within  the  alveoli  nucleated  cor- 
-  which  very  frequently  contain  dark  particles  in  their  protoplasm. 
They  appear  to  be  amoeboid  cells  which  have  migrated  from  the  blood-vessels 
and  have  taken  in  inhaled  particles  of  carbon.  They  seem  to  pass  back  into 
the  lung  tissue,  for  similar  cells  may  be  seen  in  this.  Make  a  sketch  of  part 
of  the  wall  of  a  bronchial  tube  and  of  one  or  two  of  the  alveoli. 

3.  Mount  in  Canada  balsam  a  section  of  lung  in  which  the  pulmonary 
vessels  have  been  injected.  Study  the  general  arrangement  of  the  vessels 
with  a  low  power,  and  the  network  of  capillaries  of  the  alveoli  with  a  high 

Observe  that  the  veins  run  apart  from  the  arteries.     Sketch  the 
capillary  network  of  one  or  two  adjoining  alveoli. 


The  trachea  or  windpipe  is  a  fibrous  and  muscular  tube,  the  wall 
of  which  is  rendered  somewhat  rigid  by  Q-shaped  hoops  of  cartilage 
which  are  embedded  in  the  fibrous  tissue.  The  muscular  tissue,  which 
is  of  the  plain  variety,  forms  a  flat  band,  the  fibres  of  which  run  trans- 
versely at  the  back  of  the  tube.     The  trachea  is  lined  by  a  mucous 


120 


THE   ESSENTIALS  OF  HISTOLOGY 


membrane  (fig.  144,  a-c),  which  has  a  ciliated  epithelium  upon  its 
inner  surface.  The  epithelium-cells  have  been  already  described 
(Lesson  VII.)  ;  they  rest  upon  a  thick  basement-membrane.  The 
mucous  membrane  proper  consists  of  areolar  and  lymphoid  tissue,  and 
contains  numerous  blood-vessels  and  lymphatics.  In  its  deepest  part 
is  a  well-marked  layer  of  longitudinal  elastic  fibres  (d).  Many  small 
glands  for  the  secretion  of  mucus  are  found  in  the  wall  of  the  trachea. 
They  may  lie  either  within  the  mucous  membrane  or  in  the  submucous 


em4 


---;'  Vv- 


mm? 


Fig.  144. — Longitudinal  section  of  the  human  trachea,  including  portions 
of  two  cartilaginous  rings.     (Moderately  magnified.) 

a,  ciliated  epithelium  :  b.  basement-membrane  ;  c,  superficial  part  of  the  mucous  membrane, 
containing  the  sections  of  numerous  capillary  blood-vessels  and  much  lymphoid  tissue ;  d, 
deeper  part  of  the  mucous  membrane,  consisting  mainly  of  elastic  fibres ;  e.  submucous 
areolar  tissue,  containing  the  larger  blood-vessels,  small  mucous  glands  (their  ducts  and 
alveoli  are  seen  in  section  ).  fat.  &c.  :/.  fibrous  tissue  investing  and  uniting  the  cartilages  ; 
g,  a  small  mass  of  adipose  tissue  in  the  fibrous  layer  ;  A,  cartilage. 


areolar  tissue  (e),  or,  lastly,  at  the  back  of  the  trachea,  outside  the 
transverse  muscular  fibres. 

The  two  divisions  of  the  trachea,  the  bronchi,  are  precisely  similar 
in  structure. 

The  larynx  is  also  very  like  the  trachea  so  far  as  the  structure  of 
the  mucous  membrane  is  concerned,  but  over  the  true  vocal  cords  and 
upon  the  epiglottis,  as  well  as  here  and  there  hi  the  part  above  the 
glottis,  stratified  epithelium  is  found,  and  taste-buds  (see  Lesson 
XXVI.)  may  occur  in  this  epithelium,  except  over  the  vocal  cords. 


THE   TRACHEA  AND   LUNGS 


121 


The  lymphoid  tissue  is  especially  abundant  in  the  mucous  mem- 
brane of  the  ventricle  of  Morgagni,  and  a  large  number  of  mucous 
glands  open  into  this  cavity  and  into  that  of  the  sacculus. 

The  true  vocal  cords  are  composed  of  fine  elastic  fibres. 

The  cartilages  of  the  trachea  and  larynx  are  hyaline,  except  the 
epiglottis  and  the  cartilages  of  Santorini  and  of  Wrisberg,  which  are 
composed  of  elastic  fibro-cartilage. 


Fig.  145. — Diagrammatic  representation  of  the  ending  of  a 
bronchial  tube  in  sacculated  lnfundibula. 

The  lungs  are  formed  by  the  ramifications  of  the  bronchial  tubes 
and  their  terminal  expansions,  which  form  groups  of  sacculated  dila- 
tations {infundibula),  beset  everywhere  with  small  hemispherical 
bulgings,  known  as  the  air-cells  ox  pulmonary  alveoli. 

deb 


Fig.  146. — Portion  of  a  trahsvkbse  sectioh  of  a  bronchial  tube,  human 
G  mm.  in  diameter.     (Magnified  30  diameters.) 

a,  cartilage  and  fibrous  layer  with  mucous  sland=.  and.  in  the  outer  part,  a  little  fat  ;  in  the 
middle,  the  duct  of  a  eland  opens  on  the  inner  surface  of  the  tube;  b,  annular  layer  of 
involuntary  muscular  fibres  :  <\  elastic  layer,  the  elastic  fibres  in  bundles  which  are  seen 
cut  across  ;  d,  columnar  ciliated  epithelium. 


The  bronchial  tubes  (figs.  146,  147)  are  lined  in  their  whole 
extent  by  ciliated  epithelium  which  rests  on  a  basement-membrane. 
External  to  this  is  the  corium  of  the  mucous  membrane,  containing  a 
large  number  of  longitudinal  elastic  fibres  and  some  lymphoid  tissue. 


122 


THE   ESSENTIALS   OF  HISTOLOGY 


Outside  this  again  is  a  complete  layer  of  plain  muscular  fibres  encircling 
the  tube.  Next  comes  a  loose  fibrous  layer  in  which,  in  the  larger 
tubes  i  fig.  146),  small  plates  of  cartilage  are  embedded.  Mucous 
glands  are  also  present  hi  this  tissue. 


Fig.  147. — Section  of  a  small  bronchial  tube  from  the  pig's  long. 
(This  section  is  much  more  magnified  than  that  represented  in  the  previous 
figure.) 

a,  fibrous  layer  :  b,  muscular  layer :  c,  mucous  membrane  in  longitudinal  folds,  with  numer- 
ous longitudinally  ruuuiug  elastic  fibres  cut  across  ;  d,  ciliated  epithelium  ;  /,  surround- 
ing alveoli. 

The  smallest  bronchial  tubes,  which  are  about  to  expand  into  the 
infundibula,  gradually  lose  the  distinctness  of  the  several  layers,  their 
wall  at  the  same  time  being  greatly  thinned  out  and  becoming  bulged 
to  form  the  alveoli.  The  epithelium  also  becomes  changed ;  from 
columnar  and  ciliated  it  becomes  cubical  and  non-ciliated. 

In  the  alveoli  themselves,  besides  small  groups  of  cubical  cells, 
there  are  large  irregular  flattened  cells  (fig.  148)  which  form  an 
extremely  delicate  layer,  separating  the  blood-capillaries  from  the  air 
within  the  alveoli.  The  capillary  network  of  the  alveoli  is  very 
close  (fig.  149),  and  the  capillary  vessels  of  adjoining  alveoli  are  in 
complete  continuity,  the  vessels  passing  first  to  one  side  and  then  to 
the  other  of  the  septa  which  separate  the  adjacent  alveoli. 

Blood-vessels. — Branches  of  the  pulmonary  artery  accompany  the 
bronchial  tubes  to  be  distributed  to  the  capillary  networks  upon  the 
alveoli,  from  which  the  blood  is  returned  by  the  pulmonary  veins 
which,  pursuing  a  separate  course  through  the  tissue  of  the  lung,  join 
in  their  course  with  others  to  form  larger  vessels  which  pass  to  the 
hilus.  Branches  from  the  bronchial  arteries  are  distributed  to  the 
walls  of  the  bronchial  tubes,  and  to  the  connective  tissue  of  the  lung. 
This  tissue  intervenes  everywhere  in  small  quantity  between  the  in- 
fundibula (interstitial  tissue),  and  forms  a  distinct  layer,  containing 
much  elastic  tissue,  covering  the  surface  of  the  lung  underneath  the 


THE   TRACHEA    AND   LUNGS 


123 


Fig.  148. — Section-  of  tart  of  cat's  lung,  stained  with  nitrate  of  silver. 
(Highly  magnified.) 

The  small  granular  and  the  large  Battened  cells  of  the  alveoli  are  shown.  In  the  middle  is  a 
i]  "i  a  Lobular  bronchial  tube,  with  a  patch  of  the  granular  pavement-epithelium 
on  one  side. 


Fig.  149. — Section  of  injected  lung,  including  several  contiguous  alveoli. 
I  Highly  magnified. ) 

",  n,  free  edges  of  alveoli;  c,  c  partitions   ;  ghbouring  alveoli,  seen  in  section; 

■'  arterial  branch  giving  off  capillaries  - 
either  side  oi  el]  exhibited. 

geueous  alveolar  wall  with  nuclei  of  connective-tissue  corpuscles,  and  elastic  fibres. 


124  THE   ESSENTIALS  OF  HISTOLOGY 

serous  membrane  (subserous  tissue).  In  some  animals  tins  subserous 
layer  contains  plain  muscular  tissue,  which  is  especially  developed 
near  the  lung-apex. 

The  lymphatics  of  the  lung  form  two  sets  of  vessels,  one  set 
accompanying  the  bronchial  tubes,  and  another  set  forming  a  network 
in  the  interstitial  connective  tissue,  and  in  the  subserous  tissue.  Both 
sets  of  lymphatics  tend  towards  the  hilus  and  enter  lymphatic  glands 
at  the  root  of  the  lung.  Those  in  the  subserous  tissue  communicate 
by  means  of  stomata  between  the  epithelial  cells  of  the  serous  mem- 
brane with  the  cavity  of  the  pleura. 

The  pleura,  which  covers  the  surface  of  the  lung,  has  the  usual 
structure  of  a  serous  membrane.  It  is  provided  with  a  special  network 
of  capillary  blood-vessels,  which  are  supplied  by  branches  of  the 
bronchial  arteries. 


125 


LESSON  XXVI. 

STRUCTURE  OF  THE  TEETH,   THE   TONGUE,  AND   MUCOUS 
MEMBRANE  OF  THE  MOUTH. 

1.  Study  first  with  the  low  power  and  afterwards  with  the  high  power  a 
longitudinal  section  of  a  human  tooth  which  has  been  prepared  by  grinding. 
It  is  better  to  purchase  this  specimen,  for  the  process  of  preparation  is 
difficult  and  tedious  without  the  aid  of  special  apparatus.  Examine  carefully 
the  enamel,  the  dentine,  and  the  cement.  The  dark  appearance  of  the 
dentinal  tubules  is  due  to  their  containing  ah*  in  the  dried  specimen.  Measure 
the  diameter  of  the  enamel  prisms  and  of  some  of  the  dentinal  tubules. 
Make  sketches  from  each  of  the  tissues. 

2.  Mount  in  Canada  balsam  a  section  of  a  tooth  in  situ,  which  has  been 
decalcified  in  chroinic  or  picric  acid  and  stained  with  logwood  or  borax- 
carmine.  In  this  section  the  mode  of  implantation  of  a  tooth,  as  well  as  the 
structure  of  the  pulp,  can  be  made  out.  Make  a  general  sketch  under  a  low 
power,  and  under  a  high  power  draw  a  srnall  piece  of  the  pulp  showing  the 
processes  of  the  odontoblasts  extending  into  the  dentinal  tubules. 

3.  The  development  of  the  teeth  and  the  formation  of  their  tissues  are 
studied  in  sections  made  across  the  snout  and  lower  jaw  of  foetal  animals. 
The  preparation  should  be  stained  in  bulk  with  alcoholic  magenta,  borax- 
carmine,  or  hematoxylin,  and  embedded  hi  paraffin,  and  the  sections  mounted 
by  the  shellac-creosote  process  (see  Appendix). 

4.  Section  across  the  whole  tongue  of  a  small  mammal ;  stahi  with  log- 
wood, and  mount  in  Canada  balsam.  In  these  sections  the  arrangement  of 
the  muscular  fibres  and  the  structure  of  the  papillae  of  the  mucous  mem- 
brane may  be  studied  ;  and  if  the  organ  have  been  previously  injected,  the 
arrangement  of  the  blood-vessels  in  the  muscular  tissue  and  in  the  mucous 
membrane  will  also  be  well  seen. 


THE   TEETH. 

A  tooth  consists  of  three  calcified  tissues  :  the  enamel,  which  is  of 
epithelial  origin,  the  dentine,  and  the  cement,  or  crusta  petrosa.  The 
dentine  forms  the  mam  substance  of  a  tooth,  the  enamel  covers  the 
crown,  and  the  cement  is  a  layer  of  bone  which  invests  the  root 
(fig.  150). 

The  enamel  is  formed  of  elongated  hexagonal  prisms  (fig.  151), 
which  are  set  vertically,  or  with  a  slight  curvature  upon  the  surface  of 
the  dentine.  They  are  marked  at  tolerably  regular  intervals  with 
slight  transverse  shadings  producing  an  indistinct  cross-striated  ap- 
pearance. Sometimes  coloured  lines  run  through  the  enamel  across 
the  direction  of  its  fibres. 


126 


THE   ESSENTIALS   OF  HISTOLOGY 


The  dentine  is  composed  of  a  hard  dense  substance  like  bone,  but 
containing  no  Haversian  canals  or  lacuna?.  It  is  pierced  everywhere, 
however,  by  fine  canaliculi  {dentinal  tubules,  figs.  152,  153),  which 
radiate  outwards  from  a  central  cavity  which,  during  life,  contains  the 
pulp.  The  tubules  branch  at  acute  angles  as  they  pass  outwards  I 
their  branches  become  gradually  finer  towards  the  periphery  of  the 


Fig.  150. — Vertical 
section*  of  a  tooth 
in  situ.  (15  diame- 
ters. ) 

c,  is  placed  in  the  pulp- 
cavity,  opposite  the 
cervix  or  neck  of  the 
tooth  ;  the  part  above 
is  the  crown, that  below 
is  the  root  (fang).  1, 
enamel  with  radial  and 
concentric    markings ; 

2,  dentine  with  tubules 
and  incremental  lines  ; 

3,  cement  or  crusta  pe- 
trosa,with  bone  corpus- 
cles ;  4,  dental  perios- 
teum ;  5,  boue  of  lower 
jaw. 


dentine.  The  tubules  have  a  proper  wall  of  their  own,  which  can  be 
isolated  by  steeping  a  section  of  tooth  in  strong  hydrochloric  acid.  In 
the  living  tooth  they  are  occupied  by  protoplasmic  fibres,  which  are  pro- 
longed from  the  superficial  cells  of  the  pulp. 

The  intertubular  substance  is  for  the  most  part  homogeneous,  but 
here  and  there  indications  can  be  seen  of  its  deposition  in  the  form  of 
globules.     This  is  especially  the  case  near  the  surface  of  the  dentine, 


STRUCTURE   OF   THE    TEETH 
A 


127 


Fig.  151. — Enamel  prisms.     ^350  diameters.) 

A,  fragments  and  single  fibres  of  the  enamel,  isolated  by  the  action  of  hydrochloric  acid 

B,  surface  of  a  small  fragment  of  enamel,  showing  the  hexagonal  ends  of  the  fibres. 


Fig.  152. — Section  of  fang,  pa- 
rallel To  THE  DENTINAL  TU- 
BULE-. ( Magnified  300  diameters.) 

1,  cement,  with  large  bone-lacuna-  and 
indications  ;    2,    granular 

layer     ot     Purkinje    ( interglobular 
spaces);  3, dentinal  tubules. 


Fig.  153. — Si  <  rioxs  or 

DENTINAL       TUBULES. 

a,  cut  across  :  b.  cut 

obliquely. 

(About  300  diameters.) 


where  the  globular  deposit  and  the  interglobular  spaces  may  produce 
a  granular  appearance  [granular  layer,  fig.  l'rl,  2),  and  also  in  the 


128 


THE  ESSENTIALS  OF  HISTOLOGY 


course  of  certain  lines  or  clefts  which  are  seen  traversing  die  dentine 
across  the  direction  of  the  tubules  [incremental  lines,  fig.  150,  shown 
magnified  in  fig.  154). 


Fig.  154. — A  small  portion  ok  the  dentine  with  interglobular  spaces. 
(350  diameters.) 

c,  portion  of  incremental  line  formed  by  the  interglobular  spaces,  which  are  here  filled  up 
by  a  transparent  material. 

The  pulp  consists  of  a  soft,  somewhat  jelly-like,  connective  tissue, 
containing  many  branched  cells,  a  network  of  blood-vessels,  and  some 
nerve  fibres  which  pass  into  the  pulp-cavity  along  with  the  blood- 
vessels by  a  minute  canal  at  the  apex  of  the  fang.  The  superficial 
cells  of  the  pulp  form  an  almost  continuous  layer,  like  an  epithelium. 
They  are  known  as  odontoblasts,  from  having  been  concerned  in  the 
formation  of  the  dentine. 

The  crusta  petrosa  (fig.  152,  l)  is  a  layer  of  lamellated  bone  in- 
cluding lacunae  and  canaliculi,  but  without  Haversian  canals,  at  least 
normally  in  the  human  teeth.  It  is  covered  with  periosteum  (dental 
'periosteum),  which  also  lines  the  socket,  and  serves  to  fix  the  tooth 
securely. 

Formation  of  the  teeth. — The  teeth  are  developed  in  the  same 
manner  as  the  hairs.  A  thickening  of  the  epithelium  occurs  along  the 
line  of  the  gums,  and  grows  into  the  corium  of  the  mucous  membrane 
(common  enamel-germ,  fig.  155,  A).  At  regular  intervals  there  is  yet  a 
further  thickening  and  growth  from  the  common  enamel-germ  into  the 
tissue  of  the  mucous  membrane,  each  of  these  special  rudiments  swelling 
out  below  into  a  flask-shaped  mass  of  cells,  the  special  enamel-germ, 
fig.  155,  B).  A  vascular  papilla  grows  up  from  the  corium  into  the 
bottom  of  the  special  enamel-germ  (fig.  155,  C,  D)  ;  this  papilla  has 
the  shape  of  the  crown  of  the  future  tooth.  Each  special  enamel- 
germ,  with  its  included  papilla,  presently  becomes  cut  off  from  the 
epithelium  of  the  mouth,  and  surrounded  by  a  vascular  membrane — 
the  dental  sac.  The  papilla  becomes  transformed  into  the  dentine  of 
the  future  tooth,  and  the  enamel  is  deposited  upon  its  surface  by  the 
epithelial  cells  of  the  enamel-germ.  The  root  of  the  tooth,  with  its 
covering  of  cement,  is  formed  at  a  later  period,  when  the  tooth  is 


DEVELOPMENT   OF  THE   TEETH 


129 


r—~ 


l.r 


S^^v^Xg^ 


Wm 


Fig.  155. 
A.  Section  across  the  uppj  i:  jaw  of  a  FCETAL  sheep.     (3  centimeters  long.) 

1,  common  enamel-germ  dipping  down  into  the  mucous  membrane  where  it  is  half  surrounded 
bj  ;>  semilunar-shaped  more  dense-looking  tissue,  the  germ  of  the  dentine  and  dental  sac  ; 
■2,  palatine  process  of  the  maxilla. 

B.  Section    similar    ro    that    shown-    in    the    previous    figure,    but    passing 

THROUGH     ONE    OF     Till:    SPE(  IAL     ENAMEL-GERMS    HERE    BECOMING    FLASK-SHAPED. 

c,  c',  epithelium  of  mouth ;  /,  neck ;  f,  body  of  special  enamel-germ. 


C  ami  D.    Sections  at  later  stages  than  A  and  B,  the   papilla   having  be- 

COME    FORMED    AND    INDENTED     1  lit    ENAMEL-GERM,    WHICH    HAS    AT    THE    SAME    TIME 
GROWN    PARI  I.Y    ROl  NI>    IT. 

c.  epithelium  of  gum,  sketched  in  outline  :  /',  neck  of  enamel-germ;  f,  enamel-organ  ;  e,  its 

ctions  into  the  corium  :  ;•.  papilla;  I,  dental  5ac  funning. 

In  D,  the  enamel-germ  {Jp )  of  the  corresponding  permanent  tooth  has  become  formed. 


130 


THE  ESSENTIALS   OF  HISTOLOGY 


beginning  to  grow  np  through  the  gum,  by  a  gradual  elongation  of  the 
base  of  the  papilla. 

Previously  to  the  deposition  of  the  enamel,  the  enamel-germ  under- 
goes a  peculiar  transformation  of  its  previously  rounded  epithelium - 


Fig.    156.  —  A    section    through    the 

EN  AM  EL-ORGAN    AND    DENTAL    SAC    FROM 
THE      TOOTH      OF     A      CHILD      AT      BIRTH. 

(250  diameters.) 

a,  outer  dense  layer  of  the  dental  sac ;  b,  inner 
looser  texture  of  the  same  with  capillary  blood- 
vessels and  a  somewhat  denser  layer  towards 
the  enamel  organ  :  c,  spongy  substance  ;  rf,  inner 
cells  ;  aud  e,  outer  cellular  layer  of  the  euauiel- 
organ. 


Fig.  157. — Part  of  section  of  develop- 
ing TOOTH  OF  YOUNG  RAT,  SHOWING 
THE  MODE  OF  DEPOSITION  OF  THE  DEN- 
TINE.    (Highly  magnified.) 

a,  outer  layer  of  fully  calcified  dentine ;  6,  un- 
calcified  matrix,  with  a  few  nodules  of  calca- 
reous matter ;  c,  odontoblasts  with  processes 
extending  into  trie  dentine;  d,  pulp.  The  sec- 
tion is  stained  with  carmine,  which  colours 
the  uncalcified  matrix,  but  not  the  calcified 
part. 


cells  into  three  layers  of  modified  cells.  One  of  these  is  a  layer  of 
columnar  cells  (fig.  156,  d),  which  immediately  covers  the  surface 
of  the  dentine.  These  columnar  cells  form  the  enamel-prisms  either 
by  a  deposition  of  calcareous  salts  external  to  them,  or  by  a  direct 
calcification  of  their  protoplasm.  The  cells  next  to  the  dental  sac 
form  a  single  layer  of  cubical  epithelium  (e),  all  the  other  cells  of  the 


THE   TONGUE  131 

enamel-germ  become  transformed  into  branching  corpuscles  {Cj  com- 
municating by  their  processes,  and  thus  forming  a  continuous  net- 
work. The  enamel-germ,  after  it  is  thus  modified,  is  known  as  the 
enamel-organ. 

The  dentine  of  the  tooth  is  formed  by  calcification  of  the  surface  of 
the  papilla.  At  this  surface  there  is  a  well-marked  layer  of  odonto- 
blasts (fig.  157),  and  these  produce  a  layer  of  dentinal  matrix  which 
forms  a  sort  of  cap  to  the  papilla,  and  which  soon  becomes  calcified  by 
the  deposition  of  globules  of  calcareous  matter.  Processes  of  the 
odontoblasts  remain  in  the  dentine  as  it  is  forming,  and  thus  the 
dentinal  tubules  are  produced.  Subsequently  other  layers  of  dentine 
are  formed  within  the  first  by  a  repetition  of  the  same  process,  and  in 
this  way  the  papilla  gradually  becomes  calcified.  A  part,  however, 
remains  unaltered  in  the  centre  of  the  tooth,  and  with  its  covering  of 
odontoblasts  forms  the  pulp. 

The  ten  milk-teeth  are  formed  in  each  jaw  in  this  manner. 
These,  however,  become  lost  within  a  few  years  after  birth,  and  are 
replaced  by  permanent  teeth  in  much  the  same  way  that  a  new  succes- 
sion of  hairs  occurs.  A  small  outgrowth  takes  place  at  an  early  period 
from  the  enamel-germ  of  each  of  the  milk-teeth  (fig.  155,  T),fp),  and 
this  eventually  becomes  the  germ  of  the  corresponding  permanent 
tooth.  It  gradually  enlarges,  acquires  a  papilla,  forms  an  enamel- 
organ,  in  short,  passes  through  the  same  phases  of  development  as  its 
parent  germ,  and  when  the  milk-tooth  drops  out  of  the  jaw  in  conse- 
quence of  the  absorption  of  its  roots  (by  osteoclasts)  the  permanent 
tooth  grows  up  into  its  place. 

But  there  are  six  permanent  teeth  in  each  jaw  which  do  not  suc- 
ceed milk-teeth  ;  these  are  the  permanent  molars.  They  are  developed 
from  an  extension  backwards  of  the  original  epithelial  thickening 
(common  enamel-germ)  and  the  downgrowth  from  this  into  the  corium 
of  three  successive  special  enamel -germs  at  comparatively  long  intervals 
of  time.  Within  these  the  tissues  of  the  permanent  molars  become 
formed  in  a  manner  exactly  similar  to  that  in  which  the  milk-teeth  are 
developed. 


THE   TONGUE. 

The  tongue  is  mainly  composed  of  striated  muscular  fibres,  running, 
some  longitudinally,  and  others  transversely.  It  is  coveted  by  a  mucous 
membrane,  the  epithelium  of  which,  like  that  of  the  rest  of  the  mouth,  is 
thick  and  stratified,  and  conceals  microscopic  papillae  (fig.  158)  like 
those  of  the  skin.  Besides  these,  the  upper  surface  of  the  organ  is 
covered  with  larger  papilla',  which  give  it  a  rough  appearance.  These, 
which  ore  termed  the  Ungual  papilla,  are  of  three  kinds:  (1)  About 
twelve  or  thirteen  comparatively  large  circular  projections,  each  of  which 
is  surrounded  by  a  narrow  groove  (fossa),  external  to  which  the  mucous 

k2 


132 


THE  ESSENTIALS   OF  HISTOLOGY 


Fig.  158. — Section  op 
mucous  membrane 
of  mouth.  showing 
three  microscopic 

PAl'ILL.E  AND  STRA- 
TIFIED EPITHE- 
LIUM. The  blood- 
vessels HAVE  BEEN 
INJECTED.     (Toldt.) 


Fig.  159.— Section  of  circumvallate  papilla, 
ii (man.  The  figure  includes  one  side  of  the 
papilla  and  the  adjoining  part  of  the 
vallum.     (Magnified  150  diameters.)     (Heitzmann.) 

E,  epithelium  ;  G,  taste-bud  ;  C,  eoriura  with  injected  blood- 
vessels ;  M,  gland  with  duct. 


Fig.  1G0. — Section  of  fungiform 
papilla,   HUMAN,      (Heitzmann.) 

E,  epithelium  ;  Gcorium;  L,  lymphoid  tissue ; 

M,  muscular  fibres  of  tongue. 


Fig.    161. — Section     <>f     two 
filiform    papillae,     human. 

(Heitzmann.)      (Letters   as  in 
previous  figure.) 


THE   GUSTATORY   ORGANS  133 

membrane  is  raised  above  the  general  level  (vallum)  (fig.  159 1.  These 
papilla  form  a  V-shaped  line  towards  the  back  of  the  tongue  ;  they 
receive  filaments  of  the  glosso-pharyngeal  nerve,  and  have  taste-buds  in 
the  epithelium  which  covers  their  sides,  and  in  that  of  the  side  of  the 
vallum.  They  are  known  as  the  circumvallate  papilla.  (2)  All  the  rest 
of  the  papillary  surface  of  the  tongue  is  covered  by  conical  papilla,  so 
named  from  the  conical  pointed  cap  of  epithelium  which  is  borne  by 
each  ;  sometimes  this  cap  is  fringed  with  fine  epithelial  filaments,  when 
they  are  termed  filiform  (fig.  161).  (3)  Scattered  here  and  there 
amongst  the  conical  papilla?  are  other  larger  papilhe,  the  fungiform 
(fig.  160).  These  are  very  vascular,  and  lie  partly  embedded  in  little 
depressions  of  the  mucous  membrane. 

Small  tubular  glands  may  be  seen  between  the  superficial  muscular 
fibres  sending  their  ducts  to  the  surface.  Most  of  them  secrete  mucus, 
but  those  which  open  into  the  trenches  of  the  circumvallate  papillae, 
and  a  few  others  elsewhere,  yield  a  serous  secretion. 

The  mucous  membrane  at  the  back  of  the  tongue  contains  a  large 
amount  of  lymphoid  tissue. 

The  taste-buds. — The  minute  gustatory  organs  which  are  known  as 
taste-buds  may  be  seen  in  sections  which  pass  through  the  papilla? 
vallatae  or  the  papillae  fungiformes  ;  they  are  also  present  here  and 
there  in  the  epithelium  of  the  general  mucous  membrane  of  the  tongue, 
especially  at  the  back  and  sides,  and  occur  also  upon  the  under  surface 
of  the  soft  palate,  and  on  the  epiglottis.  But  they  are  most  easily 
studied  in  the  papilla?  foliatas  of  the  rabbit,  two  small  oval  areas  lying 


Fig.  162. — Tongue  of  rabbit,  showing  the  situation  of  the 

l'AI'II.L.E    I-uLlAl.E.  /;. 


on  cither  side  of  the  back  of  the  tongue  and  marked  transversely  with 
a  number  of  small  ridges  or  laminae  with  intervening  furrows  (see 
figs.  162  and  168J.  Sections  across  the  ridges  show  numerous 
taste-buds  embedded  in  the  thick  epithelium  which  clothes  their  sides. 
The  taste-buds  are  ovoid  clusters  of  epithelium-cells  which  lie  in 
cavities  in  the  stratified  epithelium  (fig.  164).  The  base  of  the  taste- 
bud  rests  upon  the  corium  of  the  mucous  membrane,  and  receives  a 
branch  of  the  glosso-pharyngeal  nerve  ;  the  apex  is  narrow  and  com- 


104 


THE   ESSENTIALS   OF  HISTOLOGY 


municates  with  the  cavity  of  the  mouth  by  a  small  pore  in  the  super- 
ficial epithelium  (gustatory  pore,  fig.  104,  p). 


i!  i  ...  n 

! 


S-f^: 


m 


Fig.  163. — Vertical  section  of  papilla  foliata  of  the  rabbit,  passing 
across  the  folle.     (Ranvier.) 

p,  central  lamina  of  the  corium  ;  v,  section  across  a  vein,  which  traverses  the  whole  length 
of  the  folia  ;  p',  lateral  lamina  in  which  the  nerve-fibres  run  ;  g,  taste-bud  ;  n,  sections 
of  nerve-bundles  ;  a,  serous  gland. 


Fig.  164. — Section  through  the  middle  of  a  taste-bud.    (Ranvier.) 

p,  gustatory  pore  ;  s,  gustatory  cell ;  r,  sustentacular  cell :  nt,  lymph-cell,  containing  fatty 
granules  ;  e,  superficial  cells  of  the  stratified  epithelium  ;  n,  nerve-fibres. 


The  cells  which   compose  the  taste-bud  are  of  two  kinds,  viz.  : 
1.  The  gustatory  cells  (fig.  165,  a),  which  are  delicate  fusiform  or 


THE   GUSTATORY  ORGANS 


135 


bipolar  cells  composed  of  the  cell-body  or  nucleated  enlargement,  and 
of  two  processes,  one  distal,  the  other  proximal.  The  distal  process  is 
nearly  straight,  and  passes  towards  the  apex  of  the  taste-bud,  where  it 
terminates  in  a  small,  highly  refracting  cilium-like  appendage,  which 
projects  into  the  pore  above  mentioned.  The  proximal  process  is  more 
delicate  than  the  other,  and  is  often  branched  and   varicose  ;  it  is 


Fig.  165 — Various  cells  from  taste-bud  of  rabbit.    (600  diameters.) 

<?,  four  gustatory  cells  from  central  part ;  6,  two  sustentacular  cells,  and  one  gustatory  cell,  in 
connection  ;  c,  three  sustentacular  cells. 


believed  to  be  directly  connected  with  an  entering  nerve-fibre.  2.  The 
sustentacular  cells  (fig.  1G5,  c).  These  are  elongated  cells,  mostly 
flattened,  and  pointed  at  their  ends  ;  they  lie  between  the  gustatory 
cells,  which  they  thus  appear  to  support,  and  in  addition  they  form  a  sort 
of  envelope  or  covering  to  the  taste-bud.  Between  the  cells  of  the  taste- 
bud  lymph-corpuscles  are  often  seen,  having  probably  wandered  here 
from  the  subjacent  mucous  membrane. 


136  THE   ESSENTIALS   OF  HISTOLOGY 


LESSON  XXVII. 

THE   SALIVARY  GLANDS. 

1.  Study  carefully  sections  of  the  submaxillary  gland  of  a  dog.  The 
gland  should  have  been  hardened  in  alcohol  and  stained  with  logwood. 
Notice  the  acini  filled  with  clear  cells,  the  nuclei  of  which  usually  he  near  the 
basement-membrane.  Notice  here  and  there,  outside  the  clear  ceUs.  demi- 
lunes or  crescents  of  small  darkly  stained  granular -looking  cells.  Observe  also 
the  sections  of  the  ducts  with  their  striated  columnar  epithelium.  Try  and 
find  a  place  where  one  of  the  ducts  is  passing  into  the  alveoli.  Sketch  under 
a  high  power.  «■ 

2.  Study  sections  of  the  parotid  gland  prepared  in  a  similar  way. 

3.  Examine  small  pieces  of  both  submaxillary  and  parotid  gland  fresh  in 
saline  solution.  In"  the  submaxillary  gland  notice  that  the  alveolar  cells  are 
swollen  out  with  clear  mucigen.  but  that  those  of  the  parotid  are  filled  with 
gramdes  (zymogen).1  Make  a  sketch  from  each  preparation  under  a  high 
power. 

4.  Prepare  a  transverse  section  of  the  oesophagus.  Notice  the  thick 
muscular  coat  partly  containing  cross-striated  fibres  and  the  mucous  mem- 
brane with  its  papillae  and  stratified  epithelium.  Look  for  mucous  glands  in 
the  areolar  coat.     Sketch  under  a  low  power. 


The  salivary  glands  may  be  looked  upon  as  typical  of  secreting 
glands  in  general.  They  are  composed  of  a  number  of  lobules  bound 
together  loosely  by  connective  tissue.  Each  small  lobule  is  formed  of 
a  group  of  saccular  or  somewhat  tubular  alveoU  or  acini  (fig.  166)  from 
which  a  duct  passes,  and  this,  after  uniting  with  other  ducts  to  form 
larger  and  larger  tubes,  eventually  leaves  the  gland  to  open  upon  the 
surface  of  the  mucous  membrane  of  the  mouth. 

The  alveoli  are  enclosed  by  a  basement-membrane,  which  is 
reticular  (fig.  167).  This  basement-membrane  is  continued  along  the 
ducts.  Within  it  is  the  epithelium,  which  in  the  alveoli  is  composed  of 
polyhedral  cells  (fig.  168,  a),  but  in  the  ducts  is  regularly  columnar, 
except  in  that  part  of  the  duct  which  immediately  opens  into  the 

1  To  study  the  changes  which  the  alveolar  cells  undergo  during  secretion,  pilo- 
carpine is  injected  subcutaneously  into  an  animal  in  sufficient  amount  to  produce 
copious  salivation  ;  after  which  the  animal  is  killed  and  its  salivary  glands  are 
examined  as  in  preparation  3.  The  granules  are  not  seen  in  preparations  that 
have  been  in  alcohol,  but  osrnic  acid  preserves  them  ;  they  are  best  seen,  however, 
in  the  fresh  tissue. 


THE   SALIVARY   GLANDS 


137 


Fig.  106. — Diagram  of  the  construction*  of  a  lobule  of  a  tubulo-bacemosb 
(aging-tubular)  mucous  glattd. 

a,  duct ;  6,  a  branch  of  the  duct ;  <•,  alveoli  as  they  lie  together  in  the  gland  ;  d,  the  same 
separated,  showing  their  connection  as  an  irregular  tube. 


Fig.  1C7. — Membraha  propria  of  two  alveoli  isolated. 

The  preparation  is  taken  from  the  orbital  gland  of  the  dog,  which  is  similar  in  structure  to  a 
mucous  salivary  gland. 


Fig.  1  Os. — Sectios  oi   the  submaxillar?  glak the  ix>g.  showing  the 

commencement  in    a  DUCT  in  the  alveoli.     (Magnified  4-JJ  diameters.) 

«,  one  of  the  alveoli,   several  <>f   which  are   in   the  section   shown    grouped    around   the 
commencement  oi  the  duct.  ■/':  »'.  an  alveolus,  not  opened  bj  the  section 
membrane  in  section  ;  e,  interstitial  connective  tissue  oi  the  gland  :  d,  section  of  a  duct 
which  has  passed  away  from  the  alveoli,  and  is  now  lined  with  characteristically  striated 

columnar  cells  ;  I,  semilunar  group  of  darkly  stained  cells  at  the  periphery  of  an  alveolus. 


138 


THE  ESSENTIALS  OF  HISTOLOGY 


Fig. 


1G9. —  Section  of  dog's  submaxillary,  stained. 
a,  duct ;  b,  alveolus  ;  c,  cresoeut. 


Fig.  170. — Section  of  part  of  the  human  submaxillary  gland. 

To  the  right  of  the  figure  is  a  group  of  mucous  alveoli,  to  the  left  a  group  of  serous  alveoli. 


Fig.  171. — Alveoli  of  a  serous  gland.    A,  at  rest.    B,  after  a  short  period 
of  activity.    C,  after  a  prolonged  period  of  activity. 

In  A  and  B  the  nuclei  are  obscured  by  the  granules  of  zymogen. 


THE   SALIVARY  GLANDS  139 

alveoli ;  in  this  it  is  flattened  (cV).  The  columnar  epithelium  of  the 
ducts  is  peculiar,  in  that  the  cells  show  a  distinction  into  two  unequal 
zones,  an  outer,  larger,  striated  zone,  and  an  inner,  smaller,  granular 
one  (fig.  168,  d). 

The  cells  of  the  alveoli  differ  according  to  the  substance  they 
secrete.  In  alveoli  which  secrete  mucus,  such  as  all  the  alveoli  of  the 
dog's  submaxillary,  and  some  of  the  alveoli  of  the  same  gland  in  man 
(fig.  170),  the  cells  are  clear  and  swollen  out  with  mucigen,  which  is 
discharged  into  the  ducts  when  the  gland  is  stimulated  to  activity.  But 
in  each  alveolus  there  are  some  smaller  cells  which  do  not  contain 
mucigen,  and  these  generally  form  crescentic  groups  which  lie  next  to 
the  basement-membrane  (fig.  169,  c).  These  are  the  so-called  crescents 
Of  Gianuzzi  ;  their  constituent  cells  are  also  known  as  marginal  cells. 
In  alveoli,  on  the  other  hand,  which  do  not  secrete  mucus,  but  watery  or 
serous  saliva,  such  as  the  parotid  in  all  animals,  and  some  of  the  alveoli 
of  the  human  submaxillary,  the  cells  are  filled  with  granules  when  the 
gland  is  at  rest,  although  the  outer  part  of  each  cell  may  become  clear 
after  a  long  period  of  secretion  (fig.  171). 

The  largest  ducts  have  a  wall  of  connective  tissue  outside  the  base- 
ment-membrane, and  also  a  few  plain  muscular  cells.  The  blood-vessels 
of  the  salivary  gland  form  a  capillary  network  around  each  alveolus. 
The  lymphatics  commence  in  the  form  of  lacunar  vessels  encircling  the 
alveoli.  The  nerve-fibres,  which  are  derived  both  from  the  cerebro- 
spinal nerves  and  from  the  sympathetic,  have  not  been  satisfactorily 
traced  to  their  termination,  but  they  probably  become  connected  with 
the  alveolar  cells. 


THE  PHARYNX  AND   (ESOPHAGUS. 

The  pharynx  is  composed  of  a  fibrous  membrane,  which  is  encircled 
by  striated  muscles,  the  constrictors,  and  lined  by  mucous  membrane. 
The  mucous  membrane  is  lined  in  the  upper  part  of  the  pharynx  and 
on  the  upper  surface  of  the  soft  palate  with  ciliated  epithelium,  which 
is  continuous  with  that  of  the  nostrils,  and  through  the  Eustachian 
tube  with  that  of  the  tympanum.  Below  the  level  of  the  soft  palate 
the  epithelium  is  stratified  like  that  of  the  mouth  and  gullet,  into 
which  it  passes.  In  certain  parts  the  mucous  membrane  contains  a 
large  amount  of  lymphoid  tissue,  especially  at  the  back,  where  it 
forms  a  projection  which  is  sometimes  termed  the  pharyngeal  tonsil, 
and  there  are  numerous  mucous  glands  opening  on  its  surface. 

The  oesophagus  or  gullet,  which  passes  from  the  pharynx  to  the 
stomach,  consists,  like  the  pharynx,  of  a  fibrous  covering,  a  muscular 
coat,  a  lining  mucous  membrane,  and  intervening  connective  tissue 
(areolar  coat)  (fig.  172).  The  muscular  coat  is  much  more  regularly 
arranged  than  that  of  the  pharynx,  and  is  composed  of  striated  muscle 
in  about  its  upper  third  only,  the  rest  being  of  the  plain  variety.    There 


140 


THE   ESSENTIALS   OF  HISTOLOGY 


are  two  layers  of  the  muscular  coat,  an  outer  layer,  in  which  the  fibres 
run  longitudinally,  and  an  inner,  in  which  they  course  circularly.  The 
mucous  membrane  is  lined  by  a  stratified  epithelium,  into  which  micro- 
scopic papilla?  from  the  corium  project.  The  corium  is  formed  of  areolar 
tissue,  and  its  limits  are  marked  externally  by  a  narrow  layer  of  longi- 


£^ 


mm 


Fig.  172. — Section  of  the  human  (esophagus. 

The  section  is  transverse,  and  from  near  the  middle  of  the  gullet,  a,  fibrous  covering ; 
b,  divided  fibres  of  the  longitudinal  muscular  coat ;  c,  transverse  muscular  fibres ;  </,  sub- 
mucous  or  areolar  layer  ;  e,  muscularis  mucosa1  ;  /.  papillae  of  mucous  membrane  ;  g,  lami- 
nated epithelial  lining  ;  h,  mucous  gland  ;  i,  gland  duct. 

tudinally  disposed  plain  muscular  fibres,  the  muscularis  mucosa.  This 
is  separated  from  the  proper  muscular  coat  by  the  areolar  coat,  which 
contains  the  larger  branches  of  the  blood-vessels  and  lymphatics,  and 
also  most  of  the  mucous  glands  of  the  membrane. 


141 


LESSON  XXVIII. 

THE  STRUCTURE   OF  THE    STOMACH. 

1.  Sections  of  the  cardiac  region  of  the  dog's  stomach,  cut  perpendicularly 
to  the  surface  of  the  mucous  membrane.  The  tissue  is  to  be  stained  with  log- 
wood  or  borax-carmine,  and  the  sections  are  to  be  mounted  in  Canada  balsam. 

In  these  sections  the  general  arrangement  of  the  coats  of  the  stomach  is  to 
be  studied  and  sketches  are  to  be  made  under  a  low  power  illustrating  this 
arrangement,  and  others  under  a  high  power  showing  the  structure  of  the 
glands  of  the  mucous  membrane. 

Measure  the  whole  thickness  of  the  mucous  membrane,  the  thickness  of 
the  muscular  coat,  the  size  of  the  columnar  epitheliuin-cells  of  the  surface, 
and  that  of  the  cells  in  the  deeper  parts  of  the  glands. 

2.  Sections  of  the  mucous  membrane  of  the  same  region,  cut  parallel 
to  the  surface. 

These  sections  will  show  better  than  the  others  the  arrangement  of  the 
cells  in  the  glands. 

3.  Vertical  sections  of  the  mucous  membrane  from  the  pyloric  region 
of  the  dog's  stomach.  Make  a  sketch  under  a  low  power  of  one  of  the  glands 
in  its  whole  length,  filling  up  some  of  the  details  with  the  high  power. 

4.  Study  the  arrangement  of  the  blood-vessels  of  the  stomach  in  vertical 
sections  of  the  wall  of  an  organ  the  vessels  of  which  have  been  injected. 


The  wall  of  the  stomach  consists  of  four  coats,  which,  enumerated 
from  without  in,  are  as  follows,  viz.:  serous,  muscular,  areolar  or  sub- 
mucous, and  mucous  membrane. 

The  serous  coat  is  a  layer  which  is  derived  from  the  peritoneum. 
It  is  deficient  only  along  the  lines  of  the  lesser  and  greater  curvatures. 

The  muscular  coat  consists  of  three  layers  of  plain  muscular  fibres. 
Of  these  the  bundles  of  the  outer  layer  run  longitudinally,  those  of  the 
middle  layer  circularly,  and  those  of  the  inner  layer  obliquely.  The 
longitudinal  and  circular  bundles  become  thicker  and  stronger  towards 
the  pylorus,  at  which  they  pass  into  the  corresponding  layers  of  the 
small  intestine;  at  the  pylorus  itself  the  circular  layer  is  greatly 
thickened  to  form  the  sphincter  muscle.  The  oblique  fibres  are  only 
present  in  the  left  or  cardiac  part  of  the  stomach. 

The  areolar  or  submucous  coat  is  a  layer  of  areolar  tissue,  which 
serves  to  unite  the  mucous  membrane  loosely  to  the  muscular  coat ; 
in  it  ramify  the  larger  branches  of  the  blood-vessels  and  lymphatics. 


142 


THE  ESSENTIALS   OF  HISTOLOGY 


Fig.  174. — A  cardiac  gland  of 

MMPLE  FORM,  FROM  THE    BAT'S 

stomach.  (Osmic  acid  prepara- 
tion.) 

c,  columnar  epithelium  of  the  surface ; 
n,  neck  of  the  gland  with  central 
and  parietal  cells  :  /.  base  or  fundus, 
occupied  only  by  principal  or  cen- 
tral cells,  which  exhibit  the  granules 
accumulated  towards  the  lumen  of 
the  gland. 


Fig.  173.— A  cardiac  gland  from  the  dog's  stomach.    (Highly  magnified.) 

d,  duct  or  mouth  of  the  gland  :  b,  base  or  fundus  of  one  of  its  tubules.    On  the  right  the  base 
of  a  tubule  nioru  highly  magnified  ;  c,  central  cell  ;  j;  parietal  cell. 


THE   STRUCTURE   OF  THE   STOMACH  143 

The  mucous  membrane  is  a  soft,  thick  layer,  generally  somewhat 
corrugated  in  the  empty  condition  of  the  organ.  Its  thickness  is 
mainly  due  to  the  fact  that  it  is  made  up  of  long  tubular  glands,  which 
open  upon  the  inner  surface.  Between  the  glands  the  mucous  mem- 
brane is  formed  of  areolar  with  much  lymphoid  tissue.  Externally  it 
is  bounded  by  the  muscularis  mucosa,  which  consists  of  an  external 
longitudinal  and  an  inner  circular  layer  of  plain  muscular  fibres.  The 
glands  are  formed  of  a  basement-membrane  lined  with  epithelium. 
Each  gland  consists  of  three  or  four  secreting  tubules,  which  open* 
towards  the  surface  into  a  larger  common  tube,  the  duct  of  the  gland. 
The  duct  is  in  all  cases  lined  by  columnar  epithelium  of  the  same 
character  as  that  which  covers  the  inner  surface  of  the  mucous  mem- 
brane, but  the  epithelium  of  the  secreting  tubules  is  somewhat  different 
from  this,  and,  moreover,  differs  somewhat  in  the  glands  of  the  cardiac 
and  pyloric  regions  of  the  organ. 

In  the  cardiac  glands  (fig.  173)  the  secreting  tubules  are  long,  and 
the  duct  short.  The  epithelium  of  the  tubules  is  composed  of  two  kinds 
of  cells.  Those  of  the  one  kind,  which  form  a  continuous  lining  to  the 
tubule,  are  somewhat  polyhedral  in  shape,  and  in  stained  sections  look 
clearer  and  smaller  than  the  others,  but  in  the  fresh  glands,  and  in 
osmic  preparations,  they  appear  filled  with  granules  (fig.  174 1.1  These 
cells  are  believed  to  secrete  the  pepsin  of  the  gastric  juice,  and  are  termed 
the  chief  cells  of  the  cardiac  glands,  or,  from  their  relative  position  in 
the  tubule  immediately  surrounding  the  lumen,  the  central  cells.  Scat- 
tered along  the  tubule,  and  lying  between  the  chief  cells  and  the  base- 
ment membrane,  are  a  number  of  other  spheroidal  or  ovoidal  cells, 
which  become  stained  by  logwood  and  other  reagents  more  darkly  than 
the  central  cells.  These  are  the  superadded  ox  parietal  cells  (oxyntic  - 
cells  of  Langley). 

In  the  pyloric  glands  (fig.  175)  the  ducts  are  much  longer  than  in 
the  cardiac  glands,  and  the  secreting  tubules  possess  cells  of  only  one 
kind.  These  correspond  to  the  chief  cells  of  the  cardiac  glands.  They 
are  of  a  columnar  or  cubical  shape,  and  in  the  fresh  condition  of  a 
granular  appearance,  and  quite  unlike  the  columnar  epithelium-cells 
of  the  surface,  which  are  long  tapering  cells,  the  outer  part  of  which 
is  filled  with  mucus.  At  the  pylorus  itself  the  pyloric  glands  become 
considerably  lengthened,  and  are  continued  into  the  submucous  tissue, 
the  muscularis  mucosa-  being  here  absent  ;  they  thus  present  transi- 
tions to  the  glands  of  Brunner,  which  lie  in  the  submucous  tissue  of 
the  duodenum,  and  send  their  ducts  through  the  mucous  membrane 
to  the  inner  surface. 

The  blood-vessels  of  the  stomach  (fig.  176)  are  very  numerous,  and 

1  The  granules  are  most  numerous  at  the  inner  part  of  the  cell,  a  small  outer 
zone  being  left  clear.  After  prolonged  activity  this  outer  zone  increases  in  size 
while  the  granules  diminish  in  number  as  in  the  analogous  cases  of  the  pancreas 
and  parotid  glands. 

2  So  called  because  they  produce  the  acid  of  the  gastric  secretion. 


144 


THE    ESSENTIALS   OF   HISTOLOGY 


pass  to  the  organ  along  its  curvatures.  The  arteries  pass  through  the 
muscular  coat,  giving  off  branches  to  the  capillary  networks  of  the 
muscular  tissue,  and  ramify  in  the  areolar  coat.  From  this,  small 
arteries  pierce  the  museulaiis  mucosae,  and  break  up  into  capillaries 
near  the  bases  of  the  glands.  The  capillary  network  extends  between 
the  glands  to  the  surface,  close  to  which  it  terminates  in  a  plexus  of 


Fig.  176. — Plan  of  the  blood- 
vessels  of  the  stomach. 

a.  small  arteries  passing  to  break  up 
into  the  fine  capillary  network.  </, 
between  the  glands ;  6,  coarser 
capillary  network  around  the 
mouths  of  the  glands  ;  c,  c,  veins 
passing  vertically  downwards  from 
the  superficial  network  ;  e,  larger 
vessels  in  the  submucosa. 


Fig.  175. — A  pyloric  gland, 

FROM      A      SECTION     OF     THE 
dog's  STOMACH. 

m,  mouth;  n,  neck  ;  Ir,  a  deep  por- 
tion of  a  tubule  cut  transversely. 


relatively  large  venous  capillaries  which  encircle  the  mouths  of  the 
glands.  From  this  plexus  straight  venous  radicles  pass  through  the 
mucous  membrane,  pierce  the  museulaiis  mucosae,  and  join  a  plexus  of 
veins  in  the  submucous  tissue.  From  these  veins  blood  is  carried 
away  from  the  stomach  by  efferent  veins,  which  accompany  the  enter- 
ing arteries. 

The  lymphatics  (fig.  177  j  arise  in  the  mucous  membrane  by  a 


THE   STRUCTURE   OF  THE   STOMACH 


145 


plexus  of  large  vessels  dilated  at  intervals,  and  looking  in  sections  like 
clefts  in  the  incerglandular  tissue.  From  this  plexus  the  lymph  is 
carried  into  larger  valved  vessels  in  the  submucous  coat,  and  from 
these,  efferent  vessels  pass  through  the  muscular  coat  to  reach  the 


Fig.  177. — Lymphatics  of  the  human  gastric  mucous  membrane,  injected. 

The  tubule-  are  only  faintly  indicated  :  '(.  muscularis  mucosae  :  b,  plexus  of  fine  vessels  at 
base  -  plexus  of  larger  valved  lymphatics  in  submucosa. 


serous  membrane,  underneath  which  they  pass  away  from  the  organ. 
The  muscular  coat  has  its  own  network  of  lymphatic  vessels.  These 
lie  between  the  two  principal  layers,  and  their  lymph  is  poured  into 
the  efferent  lymphatics  of  the  organ. 

The  nerves  have  the  same  arrangement  and  mode  of  distribution 
as  those  of  the  small  intestine  (see  next  Lesson;. 


140  THE   ESSENTIALS  OF  HISTOLOGY 


LESSONS  XXIX.   and  XXX. 

STRUCTURE    OF    T HE  INT E ST INE. 

LESSON   XXIX. 

1.  Sections  of  the  duodenum  or  jejunum  vertical  to  the  surface.  The 
tissue  is  to  be  stained  with  logwood  or  borax-carmine  and  the  sections 
mounted  in  Canada  balsam.  The  general  arrangement  and  structure  of  the 
intestinal  wall  is  to  be  studied  in  these  sections. 

Make  a  general  sketch  under  the  low  power  and  carefully  sketch  part  of 
a  villus  tmder  the  high  power. 

2.  From  the  same  portion  of  the  intestine,  sections  parallel  to  the 
surface,  and  therefore  across  the  long  axis  of  the  villi  and  glands  of  the 
mucous  membrane.  In  order  to  keep  the  sections  of  the  villi  together  so  that 
they  are  not  lost  in  the  mounting,  it  will  be  necessaiw  to  employ  the  creosote- 
shellac  method  of  mounting  the  sections  (see  Appendix). 

In  this  preparation  sketch  the  transverse  section  of  a  villus. 

3.  Transverse  vertical  sections  of  the  ileum  passing  through  a  Peyer's 
patch.  Observe  the  nodules  of  lymphoid  tissue  which  constitute  the  patch  and 
which  extend  into  the  submucous  tissue.  Notice  also  the  sinus-like  lym- 
phatic or  lacteal  vessel  which  encircles  the  base  of  each  nodule.  Make  a 
general  sketch  under  a  low  power. 

4.  To  study  the  process  of  fat-absorption,  kill  a  rat  three  or  four  hours 
after  feeding  it  with  fat  meat.  Put  a  very  small  piece  of  the  mucous  mem- 
brane of  the  intestine  into  osmic  acid  (0*5  per  cent.)  and  another  piece  into 
chromic  acid  (0"2  per  cent.)  containing  a  few  drops  of  osmic  acid  solution. 
After  forty-eight  hours  teased  preparations  may  be  made  from  the  osmic  acid 
preparation,  in  the  same  manner  as  directed  in  Lesson  VII.  §  2 ;  the  rest 
may  be  then  placed  in  alcohol.  The  piece  in  chromic  and  osmic  acid  may 
also  after  two  or  three  days  be  placed  in  alcohol.  When  hardened  and  de- 
hydrated in  this,  the  pieces  of  tissue  are  embedded  in  paraffin,  and  sections 
are  made  and  mounted  by  the  sheUac-creosote  process. 


LESSON   XXX. 

1.  Sections  of  small  intestine  the  blood-vessels  of  which  have  been  injected. 
Notice  the  arrangement  of  the  vessels  in  the  several  layers.  Sketch  carefully 
the  vascular  network  of  a  villus. 

2.  From  a  piece  of  intestine  which  has  been  stained  with  chloride  of  gold 
tear  off  broad  strips  of  the  longitudinal  muscular  coat,  and  mount  them  in 
Farrant's  solution.  It  will  generally  be  found  that  portions  of  the  nervous 
plexus  of  Auerbach  remain  adherent  to  the  strips,  and  it  can  in  this  way 
easily  be  studied. 

From  the  remainder  of  the  piece  of  intestine  tear  off  with  forceps  the 


STRUCTURE   OF   THE  INTESTINE 


147 


fibres  of  the  circular  muscular  layer  on  the  one  side,  and  the  mucous  mem- 
brane on  the  other  side  so  as  to  leave  only  the  submucous  tissue  and  the 
muscularis  mucosae.  This  tissue  is  also  to  be  mounted  fiat  in  Farrant's 
solution  :  it  contains  the  plexus  of  Meissner. 

Sketch  a  small  portion  of  each  plexus  under  a  high  power. 

3.  Sections  of  the  large  intestine,  perpendicular  to  the  surface.  These 
will  show  the  general  structure  and  arrangement  of  the  coats.  Sketch  under 
a  low  power. 

4.  Sections  of  the  mucous  membrane  of  the  large  intestine  parallel 
to  the  surface,  and  therefore  across  the  glands.  Sketch  some  of  the  glands 
and  the  interglandular  tissue  under  a  high  power. 

5.  The  arrangement  of  the  blood-vessels  of  the  large  intestine  may  be 
studied  in  sections  of  the  injected  organ. 


THE    SMALL   INTESTINE. 


The  wall  of  the  small  intestine  consists,  like  the  stomach,  of  four 
coats. 

The  serous  coat  is  complete  except  over  part  of  the  duodenum. 


Fig.  178. — Plexus  of  Auerba<  h.  between  the  two  layers  of  the  muscular 
coat  of  iiiK  intestine.     (Cadiat.) 


The  muscular  coat  is  composed  of  two  layers  of  muscular  tissue,  an 
outer  longitudinal  and  an  inner  circular.  Between  them  lies  a  net- 
work of  lymphatic  vessels  and  also  the  close  gangliated  plexus  of  non- 


148 


THE   ESSENTIALS   OF  HISTOLOGY 


medullated  nerve-fibres  known  as  the  plexus  myentericus  of  Auerbach. 
The  ganglia  of  tins  plexus  may  usually  be  seen  in  vertical  sections  of 
the  intestinal  wall,  but  the  plexus,  like  the  one  in  the  submucous  coat 
immediately  to  be  described,  can  only  be  properly  displayed  hi  prepara- 
tions made  with  chloride  of  gold  (fig.  178). 

The  submucous  coat  is  like  that  of  the  stomach ;  in  it  the  blood- 
vessels and  lymphatics  ramify  before  entering  or  after  leaving  the 
mucous  membrane,  and  it  contains  a  gangliated  plexus  of  nerve-fibres — 


Fig.  179. — Plexus  of  Meiss.ver  from  the  submucous  coat  of  the  intestine. 

(Cadiat.) 


the  plexus  of  Meissner — which  is  finer  than  that  of  Auerbach  and  has 
fewer  ganglion-cells  ifig.  179).  Its  branches  are  chiefly  supplied  to  the 
muscular  fibres  of  the  mucous  membrane. 

The  mucous  membrane  is  bounded  next  to  the  submucous  coat  by 
a  double  layer  of  plain  muscular  fibres  i  muscularis  mucosa].  Bundles 
from  this  pass  inwards  through  the  membrane  towards  its  inner  sur- 
face and  penetrate  also  into  the  villi.  The  mucous  membrane  proper 
is  pervaded  with  simple  tubular  glands— the  crypts  of  Lieberkuhn  — 
which  are  lined  throughout  by  a  columnar  epithelium  like  that  which 
covers  the  surface  and  the  villi.     The  mucous  membrane  between  these 


STRUCTURE   OF  THE  INTESTINE 


149 


glands  is  mainly  composed  of  lymphoid  tissue,  which  is  aggregated  at 
intervals  into  more  solid  nodules  (fig.  181 1  constituting  when  they  occur 
singly  the  so-called  solitary  glands  of  the  intestine,  and  when  aggregated 


^Sl:- 


Fig.  180. — Cross-section  of  a  small  fragment  of  the  mucous  membrane 
of  the  intestine,  including  one  entire  crypt  of  lleberkv  un  and 
parts  of  THBEE  OTHEP.s.     (  Magnified  400  diameters.) 

a,  cavity  of  the  tubular  glands  or  crypts  :  6,  one  of  the  lining  epithelial  cells  ;  c,  the  inter- 
glandular  tissue ;  d,  lymph-cells. 


m .  - 

■  i  •  :•■ 


-  •  >.  i  \  i  >  j  ■  ■ 


Fig.  181. — Section  of  the  ileum  through  a  lymphoid  nodule.     (Cadiat.) 

a.  middle  of  the  nodule  with  the  lymphoid  tissue  partly  fallen  away  from  the   - 

b,  epithelium  of  the  intestine  ;  c,  villi :  their  epithelium  is  partly  broken  away  ;  d,  crypts 
of  Lieberktthn. 


together  form  the  agminated  glands  or  patches  of  Peycr.     The  latter 
occur  chiefly  in  the  ileum. 

The  villi  with  which  the  whole  of  the  inner  surface  of  the  small 


150 


THE    ESSENTIALS   OF   HISTOLOGY 


intestine  is  closely  beset  are  clavate  or  finger-shaped  projections  of  the 
mucous  membrane,  and  are  composed,  like  that,  of  lymphoid  tissue  and 
covered  with  columnar  epithelium  (fig.  182).  The  characters  of  this 
have  been  already  described  (Lesson  VII.).  Between  and  at  the  base 
of  the  epithelium-cells  many  lymph-corpuscles  occur.  The  epithelium 
rests  upon  a  basement-membrane  formed  of  flattened  cells.  In  the 
middle  of  the  villus  is  a  lacteal  vessel  (c.  I)  which  is  somewhat 
enlarged  near  its  commencement.     Surrounding  this  vessel  are  small 


Fig.  182. — Cross-sectiox  of  a  villus  of  the  cat's  ixtesttxe. 

columnar  epithelium  :  g.  goblet  cell,  its  mucus  is  seen  partly  exuded:  7.  lymph-corpuscles 
between  the  epitheiium-cells  ;  6,  basement-membrane  ;  c,  blood-capillaries  ;  m,  section 
of  plain  muscular  fibres  ;  c.  I,  central  lacteal. 


Fig.  183. — Magnified  view  of  the  blood-vessels  of  the  intestinal  villi. 

The  drawing  was  taken  from  a  preparation  injected  by  Lieberkuhn,  and  shows,  belonging  to 
each  villus,  a  small  artery  and  vein  with  the  intermediate  capillary  network. 


bundles  of  plain  muscular  tissue  prolonged  from  the  muscularis  mucosa?. 
The  network  of  blood -capillaries  (fig.  183)  lies  for  the  most  part  near 
the  surface  within  the  basement -membrane  ;  it  is  supplied  with  blood 
by  a  small  artery  which  joins  the  capillary  network  at  the  base  of  the 
villus  ;  the  corresponding  vein  generally  arises  nearer  the  extremity. 
The  lymphatics  (lacteals)  of  the  mucous  membrane  (fig.  184 1,  after 


STRUCTURE   OF   THE   INTESTINE 


151 


receiving  the  central  lacteals  of  the  villi,  pour  their  contents  into  a 
plexus  of  large  valved  lymphatics  which  lie  in  the  submucous  tissue 
and  form  sinuses  around  the  bases  of  the  lymphoid  nodules.  From 
the  submucous  tissue  efferent  vessels  pass  through  the  muscular  coat, 
receiving  the  lymph  from  an  intramuscular  plexus  of  lymphatics,  and 
are  conveyed  away  between  the  layers  of  the  mesentery. 


y  f 


Fig.  184. — Vertical  section  of  a  portion  of  a  pah  h  of  Peter's  glands,  with 
the  lacteal  VESSELS  injected.     (32  diameters.)     (Frev.) 

The  specimen  is  from  the  lower  part  of  the  ileum  :  a,  villi,  with  their  lacteals  left  white  ; 
6,  some  of  the  tubular  glands  ;  c  the  muscular  layer  of  the  mucous  membrane  ;  d,  cupola 
or  projecting  part  of  the  nodule;  e,  central  part;/,  the  reticulated  lacteal  vessels  occu- 
pying the  lymphoid  tissue  between  the  nodules,  joined  above  by  the  lacteals  from  the 
villi  and  mucous  surface,  and  passing  below  into  g,  the  sinus-like  lacteals  under  the 
nodules,  which  again  pass  into  the  large  efferent  lacteals,  g' ;  i,  part  of  the  muscular  coat. 

Absorption  of  fat. — The  lymph-corpuscles  of  the  villi  are  the  chief 
agents  hi  effecting  the  passage  of  fat-particles  into  the  lacteals.  In 
order  to  study  this  process  of  transference,  it  is  convenient  to  stain*" 
the  fat-particles  with  osmic  acid,  which  colours  them  black.  It  can 
then  be  observed  that  in  animals  which  have  been  fed  with  fat  these 
particles  are  present  (1)  in  the  columnar  epithelium-cells;  (2)  in  the 
lymph-cells  ;  and  (3)  in  the  central  lacteal  of  the  villus.  The  lymph- 
cells  are  present  not  only  in  the  reticular  tissue  of  the  villus,  but  also 
in  considerable  number  between  the  epithelium-cells  ;  and  they  can 
also  be  seen  in  thin  sections  from  osmic  preparations  within  the  com- 
mencing lacteal ;  but  in  the  last  situation  they  are  hi  every  stage  of 
disintegration. 

Since  the  lymph-cells  are  amoeboid,  it  is  probable  from  these  facts 
that  the  mechanism  of  fat-absorption  consists  of  the  following  pro- 
cesses— viz.  il)  absorption  of  fat  into  the  columnar  epithelium-cells  of 
the  surface;  (2)  inception  of  fat  by  the  lymph-corpuscles  in  the  epi- 
thelium, partly  from  the  epithelium-cells,  and  partly,  perhaps,  directly 


152 


THE   ESSENTIALS   OF   HISTOLOGY 


from  the  intestinal  contents;  (3)  migration  of  the  lymph-corpuscles 
carrying  the  incepted  fat-particles  by  their  amoeboid  movements  through 
the  tissue  of  the  villus  and  into  the  central  lacteal;  (4)  disintegration 
and  solution  of  the  immigrated  lymph-corpuscles,  and  setting  free  both 
of  their  fatty  contents  and  also  of  the  proteid  matters  of  which  they 
are  themselves  composed. 


Fig.  185,  A. — Section  of  the  villus  of  a  rat  killed  during  fat-absorption. 

ep,  epithelium  :  sir,  striated  border :  c,  lymph-cells :  c',  lymph-cells  in  the  epithelium ; 
I,  central  lacteal  containing  disintegrating  lymph-corpuscles. 

Fig.  185,  B. — Mucous  membrane  of  frog's  intestine  during  fat-absorption. 
ep,  epithelium  ;  str,  striated  border  ;  c,  lymph-corpuscles  ;  I.  lacteal. 

This  migration  of  the  lymph-corpuscles  into  the  lacteals  of  the 
villi  is  not  a  special  feature  of  fat-absorption  alone,  but  occurs  even 
when  absorption  of  other  matters  is  proceeding ;  so  that  the  transfer- 
ence of  fat -particles  is  merely  a  part  of  a  more  general  phenomenon 
accompanying  absorption. 


THE   LARGE   INTESTINE. 

The  large  intestine  has  the  usual  four  coats,  except  near  its  ter- 
mination, where  the  serous  coat  is  absent.  The  muscular  coat  is  pecu- 
liar in  the  fact  that  along  the  caecum  and  colon  the  longitudinal 
muscular  fibres  are  gathered  up  into  three  thickened  bands  which  pro- 
duce puckerings  in  the  wall  of  the  gut. 


STRUCTURE   OF   THE   INTESTINE 


153 


The  mucous  membrane  of  the  large  intestine  is  beset  with  simple 
tubular  glands  somewhat  resembling  the  crypts  of  Lieberkiihn  of  the 
small  intestine,  and  lined  by  columnar  epithelium  similar  to  that 
of  the  inner  surface  of  the  gut,  but  containing  many  more  mucus- 
secreting  or  goblet  cells  (fig.  186).  The  extremity  of  each  gland  is 
usually  slightly  dilated.     The  interglandular  tissue  is  like  that  of  the 


Fig.    186.  —  A    gland   of   the 

LARGE  INTESTINE  OF  THE  DOG. 

(From  Heidenhain  and  Klose.) 

6,  In  longitudinal,    c,  in  transverse 
section. 


stomach,  as  is  also  the  arrangement  of  the  blood-vessels  and  lymphatics 
in  it.  The  nerves  of  the  large  intestine  also  resemble  those  of  the 
small  intestine  and  stomach  in  their  arrangement. 

At  the  lower  end  of  the  rectum  the  circular  muscular  fibres  of  the 
gut  become  thickened  a  little  above  the  anus  so  as  to  form  the  internal 
sphincter  muscle.  In  this  region  also  there  are  a  number  of  compound 
racemose  mucous  glands  opening  on  to  the  surface  of  the  mucous 
membrane. 


154  THE  ESSENTIALS  OF  HISTOLOGY 


LESSON   XXXI. 

STRUCTURE   OF  THE   LIVER    AND  PANCREAS. 

1.  Make  sections  of  liver  and  study  them  carefully  with  a  low  and  high 
power.  Sketch  the  general  arrangement  of  the  cells  in  a  lobule  under  the 
low  power  and  under  the  high  power.  Make  very  careful  drawings  of  some 
of  the  hepatic  cells  and  also  of  a  portal  canal. 

2.  Study,  first  of  all  with  the  low  and  afterwards  with  a  high  power,  a 
section  of  the  liver  in  which  both  the  bli  »<  id-vessels  and  the  bile-ducts  have  been 
injected.  Make  a  general  sketch  of  a  lobule  under  the  low  power  and  draw  a 
small  part  of  the  network  of  bile-canaliculi  under  the  high  power. 

3.  Tease  a  piece  of  fresh  liver  in  salt  solution  for  the  study  of  the  appear- 
ance of  the  hepatic  cells  in  the  recent  living  condition. 

4.  Prepare  sections  of  the  pancreas  from  a  gland  which  has  been  hardened 
in  alcohol.  The  sections  are  stamed  with  borax-carmine  and  mounted  in 
the  usual  way  in  Canada  balsam. 

Make  a  sketch  under  the  low  power. 

5.  Tease  a  small  piece  of  fresh  pancreas  in  salt  solution.  Notice  the 
granules  in  the  alveolar  cells,  chiefly  accumulated  in  the  half  of  the  ceU  which 
is  nearest  the  hunen  of  the  alveolus,  leaving  the  outer  zone  of  the  cell  clear. 

Sketch  a  small  portion  of  an  alveolus  under  a  high  power. 


THE   LIVER. 

The  liver  is  a  solid  glandular  mass,  made  up  of  the  hepatic 
lobules.  These  are  polyhedral  masses  (about  1  mm.  in  diameter i  of 
cells,  separated  from  one  another  by  connective  tissue.  In  some 
animals,  as  in  the  pig,  this  separation  is  complete,  and  each  lobule  is 
isolated,  but  in  man  it  is  incomplete.  There  is  also  a  layer  of  con- 
nective tissue  underneath  the  serous  covering  of  the  liver,  and  forming 
the  so-called  capsule  of  the  organ. 

The  blood-vessels  of  the  liver  (portal  vein  and  hepatic  artery)  enter 
it  on  its  under  surface,  where  also  the  bile-duct  passes  away  from  the 
gland.  The  branches  of  these  three  vessels  accompany  one  another 
in  their  course  through  the  organ,  and  are  enclosed  by  loose  connec- 
tive tissue  (capsule  of  Grlisson),  in  which  are  lymphatic  vessels,  the 
whole  being  termed  a  portal  canal  (fig.  187).  The  smallest  branches 
of  the  vessels  penetrate  to  the  intervals  between  the  hepatic  lobules, 
and  are  known  as  the  interlobular  branches.  The  blood  leaves  the 
liver  at  the  back  of  the  organ  by  the  hepatic  veins  :  the  branches  of 
these  run  through  the  gland  unaccompanied  by  other  vessels  (except 


STRUCTURE   OF   THE   LIVER 


156 


lymphatics)  and  can  also  be  traced  to  the  lobules,  from  each  of  which 
they  receive  a  minute  branch  I  intralobular  vein)  which  passes  from  the 
centre  of  the  lobule,  and  opens  directly  into  the  (sublobular)  branch 
of  the  hepatic  vein. 


Fig.  187. — Section  of  a  portal  canal. 

a,  branch  of  hepatic  artery  :  v,  branch  of  portal  vein  :  d,  bile-duct :  /./,  lymphatics  in  the 
areolar  tissue  of  Glisson's  capsule  which  encloses  the  vessels. 


Fig.  188. — Diagrammatic  representation  of  two  hepatic  lobules. 

The  left-hand  lobule  is  represented  with  the  intralobular  vein  out  across  ;  in  the  risht-hand 
one  the  section  takes  the  '-cur-.-  of  the  intralobular  vein,  p,  interlobular  branches  of  the 
portal  vein;  h  Intralobular  branches  of  the  hepatic  reins;  s,  sublobular  vein ;  c,  capil- 
laries of  the  lobules.  The  arrows  indicate  the  direction  of  the  course  of  the  blood.  The 
liver-cells  are  onlj  represented  in  one  part  oi  each  Lobule. 


Each  lobule  is  a  mass  of  hepatic  cells  pierced  everywhere  with  a 
network  of  blood-capillaries  ifi,^r.  188),  which  arise  at  the  periphery  of 
the  lobule,  there  receiving  blood  from  the  interlobular  branches  of  the 
portal  vein  (p),  and  converge  to  the  centre  of  the  lobule,  where  they 
unite  to  form  the  intralobular  branch  of  the  hepatic  vein.     The  inter- 


156  THE   ESSENTIALS   OF  HISTOLOGY 

lobular  branches  of  the  hepatic  arteries  join  this  capillary  network  a 
short  distance  from  the  periphery  of  the  lobule. 

The  hepatic  cells  (fig.  189 1,  which  everywhere  lie  between  and  sur- 
round the  capillaries,  are  polyhedral,  somewhat  granular  -looking  cells, 


Fig.  189. — Section  of  rabbit's  liver  with  the  intercellular  network  of 
bile-canaliculi  injected.       (Highly  magnified.)     (Hering.) 

Two  or  tliree  layers  of  cells  are  represented  ;  6,  b.  blood-capillaries. 

each  containing  a  spherical  nucleus.  After  a  meal,  the  cells  in  the 
outer  part  of  the  lobule  may  become  filled  with  fat,  and  masses  of 
glycogen  can  also  frequently  be  seen  within  the  cells. 

The  bile-ducts  commence  between  the  hepatic  cells  in  the  form  of 
fine  canaliculi,  which  lie  between  the  adjacent  sides  of  two  cells,  and 
form  a  close  network,  the  meshes  of  which  correspond  in  size  to  the 
cells  (fig.  189).  At  the  periphery  of  the  lobule  these  fine  canaliculi 
pass  into  the  interlobular  bile-ducts  (fig.  190),  the  columnar  epithe- 
lium-cells of  which  become,  by  a  gradual  transition,  changed  into 
cubical  and  polyhedral  cells,  which  join  those  of  the  hepatic  lobules. 

The  bile-ducts  are  lined  by  clear  columnar  epithelium  (fig.  187,  d). 
Outside  this  is  a  basement-membrane,  and  in  the  larger  ducts  some 
fibrous  and  plain  muscular  tissue.  Many  of  the  larger  ducts  are  beset 
with  small  cascal  diverticula. 

The  gall-bladder  is  in  its  general  structure  similar  to  the  larger  bile- 
ducts.  It  is  lined  by  columnar  epithelium,  and  its  wall  is  formed  of 
fibrous  and  muscular  tissue. 

The  lymphatics  of  the  liver  are  said  to  commence  as  perivascular 
lymphatic  spaces  enclosing  the  capillaries  of  the  lobules.  Efferent 
lymphatics  pass  away  from  the  organ  in  the  connective  tissue  which 
invests  the  portal  and  hepatic  veins. 


STRUCTURE   OF   THE   PANCREAS 


157 


Fig.  190. — Lobule  of  rabbit's  liver,  vessels  and  bile-ducts  injected. 

(Cadiat.) 

a,  central  vein  ;  6,  b,  peripheral  or  interlobular  veins ;  c,  interlobular  bile-duct. 


THE   PANCREAS. 

The  pancreas  is  a  tubulo-racemose  gland,  resembling  the  salivary 
glands,  so  far  as  its  general  structure  is  concerned,  but  differing  from 
them  in  the  fact  that  the  alveoli,  in  place  of  being  saccular,  are  longer 
and  more  tubular  in  character  (fig.  191 ).  Moreover,  the  connective  tissue 
of  the  gland  is  somewhat  looser,  and  there  occur  in  it  at  intervals 
small  groups  of  epithelium-like  cells,  which  are  supplied  with  a  close 
network  of  convoluted  capillary  vessels ;  their  function  is  unknown, 
but  their  presence  is  very  characteristic  of  the  pancreas. 

The  cells  which  line  the  alveoli  are  columnar  or  polyhedral  in 
shape.     When  examined  in  the  fresh  condition,  or  in  osmic  prepara- 


158 


THE  ESSENTIALS   OF  HISTOLOGY 


tions,  their  protoplasm  is  filled  in  the  inner  two-thirds  with  small 
granules,  but  the  outer  third  is  left  clear  (fig.  192,  A).   After  a  period  of 


im®0$Sk* 


Fig.  191. — Section  of  the  pancreas  of  the  dog. 

d,  termination  of  a  duct  in  the  tubular  alveoli,  ah: 


B. 

Fig.  192. — Part  of  ax  alveolus  of  the  rabbit's  pancreas,  A,  at  rest; 
B,  after  active  secretion.     (Foster,  after  Kiihne  and  Lea.) 

a,  the  inner  granular  zone,  which  in  A  is  larger  and  more  closely  studded  with  fine  granules 
than  in  B,  in  which  the  granules  are  fewer  and  coarser  :  b,  the  outer  transparent  zone, 
small  in  A,  larger  in  B,  and  in  the  latter  marked  with  faint  striae;  c.  the  lumen,  very 
obvious  in  B,  but  indistinct  in  A  ;  d,  an  indentation  at  the  junction  of  two  cells,  only 
seen  in  B. 


activity  the  clear  part  of  the  cell  becomes  larger,  and  the  granular 
part  smaller  (B).  In  stained  sections  the  outer  part  is  coloured  more 
deeply  than  the  inner. 

In  the  centre  of  each  acinus  there  may  generally  be  seen  some 
spindle-shaped  cells,  the  nature  of  which  (whether  epithelial  or  con- 
nective tissue)  has  not  been  determined  (centro- acinar  cells  of  Lan- 
gerhans). 


159 


LESSON   XXXII. 

STRUCTURE  OF  THE   SPLEEN,  SUPRARENAL   CAPSULE,  AND 
THYROID  BODY. 

1.  Sections  of  the  spleen  stained  with  logwood.  Notice  the  trabecular  extend- 
ing into  the  substance  of  the  organ  from  the  capsule.  Notice  also  that  the 
glandular  substance  is  of  two  kinds,  (1)  lymphoid  tissue  accumulated  round 
the  smaU  arteries  and  here  and  there  massed  to  form  lymphoid  nodules — the 
Malpighian  corpuscles  of  the  spleen — and,  (2)  a  tissue  consisting  of  a 
reticulum  of  branched  and  flattened  cells  containing  blood  in  its  interstices 
and  pervaded  by  capillaries  and  venous  radicles. 

Sketch  part  of  a  section  under  a  low  power  and  a  small  portion  of  the 
reticulum  under  a  high  power. 

2.  Sections  across  a  suprarenal  capsule.  Examine  first  with  a  low 
power,  noticing  the  general  arrangement  and  extent  of  the  cortical  and 
medullary  parts  of  the  organ,  making  a  general  sketch  which  shall  include 
both.  Afterwards  sketch  carefully  under  the  high  power  a  group  of  cells 
from  each  part  of  the  organ. 

3.  Sections  of  the  thyroid  body  stained  with  logwood.  Notice  the  vesicles 
lined  with  cubical  epithelium  and  filled  with  a  '  colloid  '  substance  which  be- 
comes stained  by  the  logwood.  Notice  also  in  some  parts  of  the  sections  a 
peculiar  highly  vascular  retiform  tissue.  Sketch  a  part  of  this  tissue  and  also 
one  or  two  vesicles.     Measure  several  vesicles. 


THE    SPLEEN. 


The  spleen  is  the  largest  of  the  so-called  ductless  glands.  It 
appears  to  be  connected  in  some  way  with  the  elaboration  of  the  blood, 
white  blood-corpuscles  being  certainly  formed  and  the  coloured  blood- 
corpuscles  being  probably  submitted  to  destruction  within  it. 

Like  the  lymphatic  glands,  the  spleen  is  invested  with  a  fibrous  and 
muscular  capsule  (fig.  193,  A),  and  this  again  has  a  covering  derived 
from  the  serous  membrane.  The  capsule  sends  fibrous  bands  or  tra- 
becules (b)  into  the  organ,  and  these  join  with  a  network  of  similar 
trabecular  which  pass  into  the  gland  at  the  hilus  along  with  the  blood- 
vessels. In  the  interstices  of  the  fibrous  framework  thus  constituted 
lies  a  soft  pulpy  substance  containing  a  large  amount  of  blood,  and 
therefore  of  a  deep  red  colour,  dotted  within  which  are  here  and  there 
to  be  seen  small  whitish  specks,  the  Malpighian  corpuscles  of  the  spleen 
(c,  c).  These  are  composed  of  lymphoid  tissue  which  is  gathered  up 
into  masses  which  surround  the  smaller  arteries,  whilst  the  red  pulp 
which  everywhere  surrounds  them  and  which  forms  the  bulk  of  the 


160 


THE   ESSENTIALS  OF   HISTOLOGY 


organ  is  composed  of  a  close  network  or  sponge  work  of  flattened  and 
branched  cells  like  connective-tissue  corpuscles.  Coursing  through  the 
pulp  and  communicating  with  its  interstices  are  capillary  blood-vessels 


Fig.  193. — Vertical  section  of  a  small  superficial  portion  of  the  human 

SPLEEN,  AS    SEEN   WITH   A    Low    POWER. 

A,  peritoneal  and  fibrous  covering  ;  6,  trabecular ;  c.  c,  Malpighian  corpuscle?,  in  one  of  which 
an  artery  is>een  cut  transversely,  in  the  other  longitudinally  ;  d,  injected  arterial  twigs  ; 
«,  spleen-pulp. 


Fig.  194. — Thin  section  of  spleen-pulp,  highly  magnified,  showing  the 
mode  of  origin  of  a  small  vein  in  the  interstices  of  the  pulp. 

r,  the  vein,  filled  with  blood-corpuscles,  which  are  in  continuity  with  others,  W,  filling  up  the 
interstices  of  the  retiform  tissue  of  the  pulp  ;  w,  wall  of  the  vein.  The  shaded  bodies 
amongst  the  red  blood-corpuscles  are  pale  corpuscles. 


which  are  connected  with  the  terminations  of  the  arteries  ;  whilst  in 
other  parts  venous  channels  arise  from  the  pulp,  and  bring  the  blood 
which  has  passed   into   its   interstices  from  the   arterial   capillaries 


STRUCTURE   OF  THE   SUPRARENAL   CAPSULES  161 

towards  the  larger  veins  of  the  organ,  which  run  in  the  trabecular,  and 
are  by  them  conducted  to  the  hilus.  The  arteries,  which  are  also  at 
first  conducted  from  the  hilus  along  the  trabecule  into  the  interior  of 
the  organ,  presently  leave  the  trabecular,  and  their  external  coat 
becomes  converted  into  a  thick  sheath  of  lymphoid  tissue  which  invests 
them  in  the  remainder  of  their  course,  and  in  places  becomes  swollen 
into  the  Malpighian  corpuscles  already  mentioned.  These  small 
arteries  distribute  a  few  capillaries  to  the  Malpighian  corpuscles,  and 
then  break  up  into  pencils  of  small  vessels  which  open  into  the  pulp  in 
the  manner  already  mentioned. 

The  cellular  elements  of  the  spleen-pulp  are  of  three  kinds,  viz. 
large,  amoeboid,  connective-tissue  cells,  also  called  splenic  cells,  lymph- 
corpuscles,  and  the  branched,  flattened  cells  which  form  the  sponge- 
work.  The  first-named  are  frequently  found  to  contain  coloured 
blood-corpuscles  in  their  interior  in  various  stages  of  transformation 
into  pigment. 

The  lymphatics  of  the  spleen  run  partly  in  the  trabecular  and  cap- 
sule, and  partly  in  the  lymphoid  tissue  ensheathing  the  arteries.  They 
join  to  form  larger  vessels  which  emerge  together  at  the  hilus. 


TEE   SUPRARENAL   CAPSULES. 

The  suprarenal  capsules  belong  to  the  class  of  bodies  known  as  duct- 
less glands,  but  they  are  entirely  different  in  structure  from  the  spleen 
and  lymphatic  glands.     A  section  through  the  fresh  organ  (fig.  195; 


Fig.  195. — A  vertical  section  of  the  suprarenal  body  of  a  fcetus,  twice 

THE   NATURAL    SIZE,    SHOWING    mi:    DISTINCTION    BETWEEN   THE   MEDULLARY 

AND   Col:  IK  AL    SUBSTANI  E. 

r,  issuing  vein  ;  r,  summit  of  kidney. 

shows  a  cortical  zone  which  is  striated  vertically  to  the  surface,  and  of  a 
yellowish  colour,  and  a  medulla  which  is  soft  and  highly  vascular,  and 
of  a  brownish-red  colour.  The  whole  organ  is  invested  by  a  iibrous 
capsule  which  sends  iibrous  septa  inwards  to  the  cortical  substance 
I  fig.  19G),  subdividing  this  for  the  most  part  into  columnar  groups  of  cells 
(zona  fasciculata,  c).     Immediately  underneath  the  capsule,  however, 

M 


162 


THE   ESSENTIALS  OF  HISTOLOGY 


the  groups  are  more  rounded  (zona  glomerulosa,  b),  whilst  next  to  the 
medulla  they  have  a  closely  reticular  arrangement  (zona  reticularis,  d), 
and  a  similar  disposition  both  of  the  cells  and  the  connective  tissue  is 
noticeable  throughout  the  medulla. 

The  cells  which  form  the  rounded  groups  and  columns  of  the  cortical 
substance  are  polyhedral  in  form  (fig.  197) ;  each  contains  a  clear  round 
nucleus,  and  there  are  often  yellowish  oil-globules  in  their  protoplasm. 


Fig.  196. — Vertical  section  of  supra 
renal  body.     (Magnified.) 

1,  cortical  substance  ;  2,  medullary  substance  ; 
a,  capsule ;  6,  zona  glomerulosa  ;  c.  zona 
fascieulata ;  d,  zona  reticularis ;  e,  groups 
of  medullary  cells ;/,  section  of  a  large  vein. 


Fig.  197. — Cells  and  cell-groups 
from  the  outermost  layer  of 
the  cortical  substance  of  the 
suprarenal  body. 


Fig.  198. — A  small  portion  of   the 

MEDULLARY  PART  OF  THE   SUPRA- 
RENAL CAPSULE  OF  THE  OX. 


No  blood-vessels  penetrate  between  these  cells,  both  the  blood-vessels 
and  lymphatics  of  the  cortex  running  in  the  fibrous  septa  between  the 
columns  ;  the  lymphatics  have  been  stated  to  communicate  with  fine 
spaces  which  run  between  the  cells  of  the  columns. 

The  cells  of  the  medulla  (fig.  198)  are  more  irregular  in  shape,  and 
are  often  branched.  Their  protoplasm  is  either  clear,  or  it  may  in  some 
animals  contain  a  brownish  pigment,  but  in  man  the  dark  red  colour  of 


STRUCTURE   OF  THE   THYROID   BODY 


163 


the  medulla  is  largely  due  to  the  blood  contained  in  the  large  venous 
spaces  by  which  it  is  pervaded,  and  which  receive  the  blood  after  it  has 
traversed  the  capillaries  of  the  cortex.  Investing  the  larger  veins  are 
bundles  of  plain  muscular  fibres  ;  and  numerous  nerves,  after  traversing 
the  cortical  substance,  are  distributed  throughout  the  medulla,  where 
they  form  a  close  plexus  provided  with  ganglion-cells. 


THE    THYROID   BODY. 

The  thyroid  body  consists  of  a  framework  of  connective  tissue  en- 
closing numerous  spherical  or  oval  vesicles  (fig.  199)  which  are  lined 
with  cubical  epithelium.  The  cavities  of  the  vesicles  are  filled  with  a 
peculiar  viscid  liquid  which  is  coagulated  by  alcohol  and  which  then 
becomes  stained  by  hematoxylin.     A  similar  material  has  been  found 


Fig.  199. — Section  of  the  thyroid  gland  of  a  child. 

Two  complete  vesicles  and  portions  of  others  are  represented.  The  vesicles  are  filled  with 
colloid,  which  also  occupies  the  interstitial  spaces.  In  the  middle  of  one  of  the  spaces  a 
blood-vessel  is  seen  cut  obliquely,  and  close  to  it  is  a  plasma-cell.  Between  the  cubical 
epithelium-cells,  smaller  cells  like  lymph-corpuscles  are  here  and  there  seen. 

in  the  lymphatics  of  the  gland,  and  may  sometimes  be  detected  also  hi 
the  interstices  of  the  connective  tissue. 

The  blood-vessels  of  the  thyroid  are  exceedingly  numerous,  and  the 
capillaries  form  close  plexuses  round  the  vesicles.  Some  of  the  blood- 
vessels are  distributed  to  a  peculiar  highly  vascular  retiform  tissue 
which  occurs  in  patches  here  and  there  in  the  organ. 

Disease  of  the  thyroid  or  its  extirpation  is  accompanied  by  remark- 
able changes  in  the  chemical  composition  of  the  blood  and  many  of  the 
tissues,  resulting  chiefly  in  the  accumulation  within  them  of  a  large 
amount  of  ))tit<-iii ;  a  condition  of  general  myxedema,  and  eventually  of 
cretinism,  being  produced. 


m2 


104  THE  ESSENTIALS  OF  HISTOLOGY 


LESSON   XXXIII. 
STRUCTURE   OF  THE   KIDNEY. 

1.  Sections  passing  through  the  whole  kidney  of  a  small  mammal,  such  as  a 
mouse  or  rat.  These  sections  will  show  the  general  arrangement  of  the  organ 
and  the  disposition  of  the  tubules  and  of  the  Malpighian  corpuscles. 

A  general  sketch  should  be  made  of  one  of  these  sections  under  a  low 
power. 

2.  Thin  sections  of  the  kidney  of  a  larger  mammal,  such  as  the  dog,  may 
next  be  studied.  In  some  the  direction  of  the  section  should  be  parallel 
with  the  tubules  of  the  medulla,  and  in  others  across  the  direction  of  those 
tubules.  The  characters  of  the  epithelium  of  the  several  parts  of  the  uriniferous 
tubules  are  to  be  made  out  in  these  sections. 

3.  Separate  portions  of  the  uriniferous  tubules  may  be  studied  in  teased 
preparations  from  a  kidney  which  has  been  subjected  to  some  process 
which  renders  it  possible  to  unravel  the  uriniferous  tubules  for  a  certain 
distance.1 

4.  Sections  of  a  kidney  in  which  the  blood-vessels  have  been  injected. 
Examine  these  with  a  low  power  of  the  microscope.  Try  and  follow  the 
course  of  the  arteries — those  to  the  cortex  sending  their  branches  to  the 
glomeruli,  those  to  the  medulla  rapidly  dividing  into  pencils  of  fine  vessels 
which  run  between  the  straight  uriniferous  tubules  of  that  part.  Notice  also 
the  efferent  vessels  from  the  glomeruli  breaking  up  into  the  capillaries  which 
are  distributed  to  the  tubules  of  the  cortical  substance. 

Make  sketches  showing  these  points. 


The  kidney  is  a  compound  tubular  gland.  To  the  naked  eye  it  ap- 
pears formed  of  two  portions — a  cortical  and  a  medullary — the  latter 
being  subdivided  into  a  number  of  pyramidal  portions  ( pyramids  of 
Malpighi),  the  base  of  each  being  surrounded  by  cortical  substance,  while 
the  apex  projects  in  the  form  of  a  papilla  into  the  dilated  commence- 
ment of  the  ureter  (pelvis  of  the  kidney).*  Both  cortex  and  medulla 
are  composed  entirely  of  tubules — the  uriniferous  tubules — which  have 
a  straight  direction  in  the  medulla  and  a  contorted  arrangement  in  the 
cortex ;  but  groups  of  straight  tubules  also  pass  from  the  medulla 
through  the  thickness  of  the  cortex  {medullary  rays). 

The  uriniferous  tubules  begin  in  the  cortical  part  of  the  organ  in 
dilatations,  each  enclosing  a  tuft  or  glomerulus  of  convoluted  capillary 

1  For  a  method  which  may  be  employed  for  this  purpose,  see  Course  of  Prac- 
tical Histology,  p.  209. 

-  In  many  animals  the  whole  kidney  is  formed  of  only  a  single  pyramid,  but 
in  man  there  are  about  twelve. 


STKUCTUKE   OF  THE   KIDNEY 


167 


Fig.  202. — Structure  of  the  epithelium  of  the  convoluted  tubules. 

d,  section  of  a  convoluted  tubule  from  the  rat,  showing  the  unaltered  proto- 
plasm occupying  a  circular  area  around  the  nucleus  of  each  cell ;  a,  b,  c, 
isolated  oells  from  the  convoluted  tubules  of  the  rat ;  e,  isolated  cells  from 
the  dog's  kidney,  viewed  from  the  inner  surface,  and  showing  the  irregular 
contour  of  the  protoplasm ;  /,  isolated  cells  from  the  newt,  showing  the 
rods  and  the  homogeneous  cuticular  layer. 


Fig.  203.— Part  of  a  con- 
voluted TUBULE  FROM 
THE   DOGS   KIDNEY. 


Fig.  204.— Portion-  of  tubules,  ISOLATED. 
(Cadiat) 

a,  large  collecting  tubule  :  b,  loop  of  Henle ;  c,  descending 
tubule  of  Heule. 


168 


THE   ESSENTIALS  OF  HISTOLOGY 


convoluted  tubules,  into  which  these  pass.  On  the  other  hand,  the 
junctional  tubule  has  a  large  lumen  and  is  lined  by  clear  flattened 
cells,  and  the  collecting  tubes  have  also  a  very  distinct  lumen  and  are 
lined  by  a  clear  cubical  or  columnar  epithelium  (figs.  201,  d;  204,  a). 


Fig.  205. — Section  across  a  papilla  of  the  kidney.     (Cadiat.) 

a,  large  collecting  tubes  (ducts  of  Bellini)  ;  b,  c,  d,  tubules  of  Henle  ;  e,f,  blood-capillaries. 

The  following  gives  a  tabular  view  of  the  parts  which  compose  a 
uriniferous  tubule,  and  the  nature  of  the  epithelium  in  each  part  : 


Portion  of  tubule 

Nature  of  epithelium 

Position  of  tubule 

Capsule 

Flattened,  reflected  over  glomerulus  . 

Labyrinth  of  cortex 

First   convoluted 

Cubical,  fibrillated,  ciliated,  the  cells 

Labyrinth  of  cortex 

tube 

interlocking 

Spiral  tube 

Cubical,  fibrillated  (like  the  last) 

Medullary  ray  of  cor- 
tex 
Boundary    zone     and 

Small  or  descend- 

Clear, flattened  cells  .... 

ing      tube      of 

partly  papillary  zone 

Henle 

of  medulla 

Loop  of  Henle    . 

Like  the  last 

Papillary  zone  of 
medulla 

Larger  or  ascend- 

Cubical, fibrillated,  sometimes  imbri- 

Medulla,  and  medul- 

ing     tube      of 

cated 

lary  ray  of  cortex 

Henle 

Zigzag  tube 

Cells  strongly  fibrillated ;  varying  in 
height ;  lumen  small 

Labyrinth  of  cortex 

Second       convo- 

Similar to  first  convoluted  tube,  but 

Labyrinth  of  cortex 

luted  tube 

cells  are  longer,  with  larger  nuclei, 
and   they   have    a   more   refractive 
aspect 

Junctional  tube  . 

Clear  flattened  and  cubical  cells 

Labyrinth  passing  to 
medullary  ray 

Straight    or    col- 

Clear, cubical  and  columnar  cells 

Medullary     ray     and 

lecting  tube 

medulla 

Duct  of  Bellini    . 

Clear,  columnar  cells  .... 

Opens  at  apex  of 
papilla 

STRUCTURE   OF   THE   KIDNEY 


169 


Blood-vessels. — The  artery  of  the  kidney  divides  into  branches 
on  entering  the  organ,  and  these  branches  pass  towards  the  cortex, 
forming  incomplete  arches  between  the  cortex  and  the  medulla  (fig. 
206,  a).  The  branches  of  the  renal  vein  form  similar  but  more  com- 
plete arches  (g).     From  the  arterial  arches  vessels  pass  through  the 


Fig.  206. — Vascular  supply  of  kiuney.  (Cadiat.) 

a,  part  of  arterial  arch ;  6,  interlobular  artery  :  c,  glomerulus  :  d,  efferent  vc>-el  pa 

medulla  as  false  art.  rect. ;  e,  capillaries  of  cortex  ;  /",  capillaries  of  medulla  ;  g,  veuous 
arch  ;  h,  straight  veins  of  medulla  ;  j,  vena  stellula ;  i,  interlobular  vein. 


cortex  (interlobular  arteries,  b),  and  give  off  at  intervals  small  arteri- 
oles (efferent  vessels  of  the  glomeruli),  each  of  which  enters  the  dilated 
commencement  of  a  uriniferous  tubule,  within  which  it  forms  a 
glomerulus.  From  the  glomerulus  a  somewhat  smaller  c/r'crcnt  vessel 
passes  out,  and  this  at  once  again  breaks  up  into  capillaries,  which 


170 


THE   ESSENTIALS   OF  HISTOLOGY 


are  distributed  amongst  the  tubules  of  the  cortex  (e)  ;  their  blood  is 
collected  by  veins  which  accompany  the  arteries  and  join  the  venous 
arches  between  the  cortex  and  the  medulla,  receiving  in  their  course 
certain  other  veins  which  arise  by  radicles  which  have  a  somewhat 
stellate  arrangement  near  the  capsule  {vena  stellula,  j). 

The  medulla  derives  its  blood- supply  from  special  offsets  of  the 
arterial  arches,  which  almost  immediately  break  up  into  pencils  of 
fine  straight  arterioles  running  in  groups  between  the  straight  tubules 
of  the  medulla.  These  arterioles  gradually  break  up  into  a  capillary 
network  with  elongated  meshes  which  pervades  the  medulla  (fig.  206,/), 
and  which  terminates  in  a  plexus  of  somewhat  larger  venous  capillaries 
in  the  papilla?.     From  these  and  from  the  other  capillaries  the  veins 


Fig.  207. — Section  through  part  of  the  dog's  kidney. 

p,  papillary,  and  g,  boundary  zones  of  the  medulla ;  c,  cortical  layer ;  A,  bundles  of 
tubules  in  the  boundary  layer,  separated  by  spaces,  b,  containing  bunches  of 
vessels  (not  here  represented),  and  prolonged  into  the  cortex  as  the  medullary 
rays,  77! ;  c,  intervals  of  cortex,  composed  chiefly  of  convoluted  tubules,  with 
irregular  rows  of  glomeruli,  between  the  medullary  rays. 

collect  the  blood,  and  pass,  accompanying  the  straight  arterioles,  into 
the  venous  arches  between  the  cortex  and  medulla.  The  groups  of 
small  arteries  and  veins  (vasa  recta)  in  the  part  of  the  medulla  nearest 
the  cortex  alternate  with  groups  of  the  uriniferous  tubules,  and  this 
arrangement  confers  a  striated  aspect  upon  this  portion  of  the  medulla 
{boundary  zone,  see  fig.  207). 

The  efferent  vessels  of  those  glomeruli  which  are  situated  nearest 
to  the  medulla  may  also  break  up  into  pencils  of  fine  vessels  (false 
arteria  recta)  and  join  the  capillary  network  of  the  medulla  (fig.  198,  d). 

Between  the  uriniferous  tubules,  and  supporting  the  blood-vessels, 
is  a  certain  amount  of  connective  tissue  (fig.  205),  within  which  are 
cleft-like  spaces  from  which  the  lymphatics  of  the  organ  originate. 


171 


LESSON  XXXIV. 

STRUCTURE   OF  THE    URETER,   BLADDER,   AND  MALE 
GENERATIVE  ORGANS. 

1.  Section  across  the  ureter. 

2.  Section  of  the  urinary  bladder  vertical  to  the  surface. 

In  the  sections  of  the  ureter  and  of  the  urinary  bladder,  notice  the 
transitional  epithelium  resting  on  a  mucous  membrane,  which  is  composed 
chiefly  of  areolar  tissue  without  glands,  and  the  muscular  coat  outside  this. 
In  the  ureter  there  is  some  fibrous  tissue  outside  the  muscidar  coat,  and  at 
the  upper  part  of  the  bladder  there  is  a  layer  of  serous  membrane  covering 
the  muscular  tissue.  Sketch  a  section  of  the  ureter  under  a  low  power,  and 
the  epithelium  of  the  bladder  under  the  high  power. 

3.  Section  across  the  penis.  The  blood-vessels  of  the  organ  should  have  been 
injected  so  as  the  better  to  exhibit  the  arrangement  of  the  venous  spaces  which 
constitute  the  erectile  tissue.  Notice  the  large  venous  sinuses  of  the  corpora 
cavernosa  and  the  smaller  spaces  of  the  corpus  spongiosum,  in  the  middle  of 
which  is  seen  the  tube, of  the  uretbra. 

4.  Section  across  the  testis  and  epididymis.  The  sections  are  best  made 
from  a  rat's  testis  which  has  been  hardened  in  alcohol  and  pieces  of  which 
have  been  stained  in  bulk  in  ddute  logwood.  In  these  sections  notice  the 
strong  capsule  surrounding  the  gland,  the  substance  of  which  consists  of 
tubules  which  are  variously  cut,  and  the  epithelium  in  which  is  in  different 
conditions  of  development  in  the  different  tubules.  Observe  the  strands  of 
polyhedral  interstitial  cells  lying  in  the  loose  tissue  between  the  tubules  and  the 
lymphatic  clefts  in  that  tissue.  Notice  also  in  sections  through  the  epididymis 
the  ciliated  epithelium  of  that  tube. 

Sketch  carefully  under  a  high  power  the  contents  of  some  of  the  semini- 
ferous tubules  so  as  to  illustrate  the  mode  of  formation  of  the  spermatozoa. 

').  Examination  of  spermatozoa.  The  spermatozoa  are  to  be  obtained 
fresh  from  the  testis  or  seminal  vesicles  of  a  recently  killed  animal  and  ex- 
amined in  saline  solution.  Their  movements  may  be  studied  on  the  warm 
stage ;  to  display  their  structure  a  very  high  power  of  the  microscope  is 
necessary.     Measure  and  sketch  three  or  four  spermatozoa. 


The  ureter  is  a  muscular  tube  lined  by  mucous  membrane.  The 
muscular  coat  consists  of  three  layers  of  plain  muscular  tissue,  an 
outer  and  inner  longitudinal  and  a  middle  circular.  Outside  the  mus- 
cular coat  is  a  layer  of  fibrous  tissue  in  which  the  blood-vessels  and 
nerves  ramify  before  entering  the  muscular  layer. 

The  mucous  membrane  is  composed  of  areolar  tissue  and  is  lined 
by  transitional  epithelium. 


172 


THE   ESSENTIALS   OF   HISTOLOGY 


The  urinary  bladder  has  a  muscular  wall  lined  by  a  strong  mucous 
membrane  and  covered  in  part  by  a  serous  coat. 

The  muscular  coat  consists  of  three  layers,  but  the  innermost  is 
incomplete.  The  principal  fibres  run  longitudinally  and  circularly, 
and  the  circular  fibres  are  collected  into  a  layer  of  some  thickness 
which  immediately  surrounds  the  commencement  of  the  urethra,  form- 
ing the  sphincter  vesica.  The  mucous  membrane  is  lined  by  a  transi- 
tional stratified  epithelium  like  that  of  the  ureter.  The  shape  and 
structure  of  the  cells  have  already  been  studied. 

The  penis  is  mainly  composed  of  cavernous  tissue  which  is  collected 
into  two  principal  tracts — the  corpora  cavernosa,  one  on  each  side,  and 
the  corpus  spongiosum  in  the  middle  line  inferiorly.  All  these  are 
bounded  by  a  strong  capsule  of  fibrous  and  muscular  tissue,  containing 
also  many  elastic  fibres  and   sending  in  strong  septa  or  trabecule, 


Fig.  208. — Section  of  erectile  tissue.     (Cadiat.) 

a,  trabecular  of  connective  tissue,  with  elastic  fibres,  and  bundles  of  plain  muscular 
tissue  (c)  ;  6,  venous  spaces. 

which  form  the  boundaries  of  the  cavernous  spaces  of  the  erectile  tissue 
(fig.  208).  The  arteries  of  the  tissue  run  in  these  trabecule,  and  their 
capillaries  open  into  the  cavernous  spaces.  On  the  other  hand,  the 
spaces  are  connected  with  efferent  veins.  The  arteries  of  the  cavernous 
tissue  may  often  in  injected  specimens  be  observed  to  form  looped  or 
twisted  projections  into  the  cavernous  spaces  [Jielicine  arteries  of 
MUllcr). 

Urethra. — The  cross-section  of  the  urethra  appears  in  the  middle 
of  the  corpus  spongiosum  in  the  form  of  a  transverse  slit.  It  is  lined 
by  columnar  epithelium,  except  near  its  orifice,  where  the  epithelium  is 
stratified.     The  epithelium  rests  upon  a  vascular  mucous  membrane, 


MALE   GENERATIVE   ORGANS 


173 


and  this  again  is  supported  by  a  coating  of  submucous  tissue,  con- 
taining two  layers  of  plain  muscular  fibres — an  inner  longitudinal  and 
an  outer  circular.  Outside  this  again  is  a  close  plexus  of  small  veins 
which  are  connected  with,  and  may  be  said  to  form  part  of,  the  coi'pus 
spongiosum. 

The  mucous  membrane  of  the  urethra  is  beset  with  small  mucous 
glands,  simple  and  compound  (glands  of  Littrc).  There  are  also  a 
number  of  oblique  recesses  termed  lacunae.  Besides  these  small  glands 
and  glandular  recesses,  two  compound  racemose  glands  open  into  the 
bulbous  portion  of  the  urethra  ( Cowper's  glands).  Their  acini  are  lined 
by  clear  columnar  cells  which  secrete  mucus. 

The  prostate,  which  surrounds  the  commencement  of  the  urethra, 
is  a  muscular  and  glandular  mass,  the  glands  of  which  are  composed 
of  tubular  alveoli,  lined  by  columnar  epithelium,  with  smaller  cells 
lying  between  them  and  the  basement-membrane.  Their  ducts  open 
upon  the  floor  of  the  urethra. 

The  integument  of  the  penis  contains  numerous  special  nerve  end- 
organs  of  the  nature  of  end-bulbs,  and  Pacinian  bodies  have  also  been 


S9.  *>+•*. 


*  s 


Fig.  209. — Transvi  rsb  sec- 
tion THROUGH  THE    RIGHT 

1 1  -nn.i:  AM'  l  in.    rUNlCA 
VAGINALIS. 

a,  connective  tissue  enveloping 
the  parietal  layer  of  the  tunica 
vaginalis;  6,  this  layer  itself; 
tunica  vagi- 
nalis :  <l.  reflected  or  visceral 
layer  adhering  t<>  e,  the  tunica 
alnuginea  :  /,  covering  of  epi- 
didymis i  g)  :  /*.  mediastinum 
testis  :  i.  branches  of  the  sper- 
matic artery :  k,  spermatic 
vein  ;  /.  vas  deferens  :  m,  small 
artery  of  the  vas  deferens  ; 
n,  o,  septa  or  processes  from  the 
mediastinum  to  the  ?urface. 


Fig.  210. — Plan  of  a  ver- 
tical SECTION  OF  THE 
TESTICLE,  SHOWING  THE 
ARRANGEMENT  OF  THE 
DUCTS. 

The  true  length  and  diameter  of 
the  ducts  have  been  disre- 
garded, a.  a,  tubuli  seminiferi 
coiled  up  in  the  separate  lobes  ; 
h,  vasa  recta  :  e,  rete  vascu- 
ln-uiii :  •/.  vasa  efferentia  end- 
ing in  theconi  vascnlosi ;  J, e,  g, 

Convoluted    canal    of    tl 

didymis ;   h.   vas   deferens :  /, 

00  of  the  back  part  of  the 
tunica  albaginea  :  i.  i.  fibrous 
processe-  running  between  the 
lobes  ;  /  to  *,  mediastinum. 


found  upon  the  nerves.     Lymphatic  vessels  are  numerous  in  the  in- 
tegument of  the  organ  and  also  in  the  submucous  tissue  of  the  urethra. 


174 


THE   ESSENTIALS   OF   HISTOLOGY 


The  testicle  is  enclosed  by  a  strong  fibrous  capsule,  the  tunica  al- 
buginea  (fig.  209,  e).  This  is  covered  externally  with  a  layer  of  serous 
epithelium  reflected  from  the  tunica  vaginalis.  From  its  inner  surface 
there  proceed  fibrous  processes  or  trabecular,  which  imperfectly  sub- 
divide the  organ  into  lobules,  and  posteriorly  the  capsule  is  prolonged 
into  the  interior  of  the  gland  in  the  form  of  a  mass  of  fibrous  tissue, 
which  is  known  as  the  mediastinum  (fig.  209,  h ).  Attached  to  the  pos- 
terior margin  of  the  body  of  the  gland  is  a  mass  [epididymis)  which 
when  investigated  is  found  to  consist  of  a  single  convoluted  tube,  receiv- 


ilfffi 


j 


y->.  it 


Q*^&2$ArXS 


Fig.  211. — Passage  of  convoluted  seminiferous  tibii.es  into  straight  tcbcles 
and  of  these  into  the  eete  testis. 

n,  seminiferous  tubules ;  b.  fibrous  stroma  continued  from  the  mediastinum  testis  ;  c,  rete  testis. 


ing  at  its  upper  end  the  efferent  ducts  of  the  testis  and  prolonged  at  its 
lower  end  into  a  thick-walled  muscular  tube,  the  vas  deferens,  which 
conducts  the  secretion  to  the  urethra. 

The  glandular  substance  of  the  testicle  is  wholly  made  up  of  convo- 
luted tubules,  which  when  unravelled  are  of  very  considerable  length. 
Each  commences  near  the  tunica  albuginea,  and  after  many  windings 
terminates,  usually  after  joining  one  or  two  others,  in  a  straight  tubule 
I  fig.  211),  which  passes  into  the  mediastinum^  and  there  forms,  by 


STRUCTURE  OF   THE   TESTICLE  175 

uniting  with  the  other  straight  tubules,  a  network  of  intercom- 
municating vessels,  which  is  known  as  the  rete  testis.  From  the  rete 
a  certain  number  of  efferent  tubules  arise,  and  after  a  few  convolutions 
pass  into  the  tube  of  the  epididymis. 

Structure  of  the  tubules. — The  seminiferous  tubules  are  formed  of 
a  basement-membrane,  and  contain  several  layers  of  epithelium-cells. 
Of  these  layers,  the  one  next  the  basement-membrane  is  a  uniform 
layer  of  clear  cubical  cells  (lining  epithelium),  the  nuclei  of  which,  for 
the  most  part,  exhibit  the  irregular  network  which  is  characteristic  of 


Z> 


is. 


/     7 


Fig.  212. — Section  of  parts  of  three  seminiferous  tubules  of  the  rat. 

a,  with  the  spermatozoa  least  advanced  in  development ;  b,  more  advanced ;  c,  containing 
fully  developed  spermatozoa.  Between  the  tubules  are  seen  strands  of  interstitial  cells 
with  blood-vessels  and  lymph-spaces. 

the  resting  condition.     Here  and  there  these  epithehum-cells  appear 
enlarged  and  to  project  between  the  more  internal  layers. 

Next  to  this  layer  of  cubical  epithelium  there  is  seen  a  layer  of 
larger  cells  \ spermatogenic  cells),  the  nuclei  of  which  have  the  skein- 
like  aspect  which  is  typical  of  commencing  division  ;  these  cells  may 
be  two,  three,  or  more  deep  I  as  in  the  tubule  a,  fig.  212).  Next  to  them, 
and  most  internal,  are  to  be  seen  in  some  tubules  [b  and  c)  a  large 
number  of  small  protoplasmic  corpuscles  with  simple  circular  nuclei 
{spermatoblasts).  In  other  tubules  these  corpuscles  are  elongated, 
and  the  nucleus  is  at  one  end,  and  in  others  again  these  elongated 
cells  are  converted  into  evident  spermatozoa,  which  lie  in  groups  with 
their  heads  projecting  between  the  deeper  cells  and  connected  with  one 
of  the  enlarged  cells  of  the  lining  epithelium,  and  their  tails  emerging 
into  the  lumen  of  the  tubule  (fig.  212,  b).  As  they  become  matured 
they  gradually  pass  altogether  towards  the  lumen,  where  they  eventually 
become  free  (c).  During  the  time  that  this  crop  of  spermatozoa  has 
been  forming,  another  set  of  spermatoblasts  has  been  produced  by  the 


170 


THE   ESSENTIALS   OF   HISTOLOGY 


division  of  the  sperniatogenic  cells,  and  on  the  discharge  of  the  sperma- 
tozoa the  process  is  repeated  as  before. 

The  straight  tubules  which  lead  from  the  convoluted  seminiferous 
tubes  into  the  rete  testis  (fig.  I'll)  are  lined  only  by  a  single  layer 
of  clear  flattened  or  cubical  epithelium.  The  tubules  of  the  rete  also 
have  a  simple  epithelial  lining,  but  the  basement-membrane  is  here 
absent,  the  epithelium  being  supported  directly  by  the  connective 
tissue  of  the  mediastinum. 

The  efferent  tubules  which  pass  from  the  rete  to  the  epididymis, 
and  the  tube  of  the  epididymis  itself,  are  lined  by  columnar  ciliated 
epithelium,  the  cilia  being  very  long  ;  these  tubes  have  a  considerable 
amount  of  plain  muscular  tissue  in  their  wall. 


Fig.  213. — Section  across  the  commencement  of 
the  vas  deferens. 

a,  epithelium  ;  b,  mucous  membrane  ;  c,  d,  e.  inner,  middle,  and 
outer  layers  of  the  muscular  coat ;  /,  bundles  of  the  internal 
cremaster  muscles  ;  g,  section  of  a  blood-vessel. 


The  vas  deferens  (fig.  213)  is  a  thick  tube,  the  wall  of  which  is 
formed  of  an  outer  thick  layer  of  longitudinal  bundles  of  plain  muscular 
tissue  ;  within  this  an  equally  thick  layer  of  circular  bundles  of  the  same 
tissue,  and  within  this  again  a  thin  layer  of  longitudinal  muscle.  The 
tube  is  lined  by  a  mucous  membrane,  the  inner  surface  of  which  is 
covered  by  columnar  non-ciliated  epithelium. 

The  connective  tissue  between  the  tubules  of  the  testis  is  of  very 


STRUCTURE   OF  THE  SPERMATOZOA.  ]77 

loose  texture,  and  contains  numerous  lymphatic  clefts,  which  form  an 
intercommunicating  system  of  commencing  lymphatic  vessels.  Lying 
in  this  intertubular  tissue  are  strands  of  polyhedral  epithelium-like 
cells  (interstitial  cells)  of  a  yellowish  colour  ;  they  are  much  more 
abundant  in  some  species  of  animals  (cat,  boarj  than  in  others.  They 
accompany  the  blood-vessels  before  these  break  up  to  form  the  capillary 
networks  which  cover  the  walls  of  the  seminiferous  tubules. 


Fig.  214. — Human  spermatozoa. 
1,  in  profile  ;  2,  viewed  on  the  flat :  6,  head  ;  c,  middle-piece  ;  d,  tail ;  e,  end-piece  of  the  tail. 

The  spermatozoa. — Each  spermatozoon  consists  of  three  parts,  a 
head,  a  middle  part  or  body,  and  a  long  tapering  and  vibratile  tail. 
In  man  (fig.  214)  the  head  is  of  a  flattened  oval  shape,  somewhat  more 
flattened  and  pointed  anteriorly ;  and  the  middle-piece  is  short  and 
cylindrical,  and  appears  to  have  a  spiral  fibre  passing  round  it ;  but  in 
different  animals  the  shape  of  the  head  and  the  extent  of  the  middle- 
piece  vary  greatly.  In  the  rat  the  head  is  long,  and  is  recurved  ante- 
riorly ;  it  is  set  obliquely  on  the  middle-piece,  which  is  also  of  con- 
siderable extent,  and  has  a  closely  wound  spiral  filament  encircling  it 
in  its  whole  length.  The  tail  is  the  longest  part  of  the  spermatozoon, 
and  during  life  is  in  continual  vibratile  motion,  the  action  resembling 
that  of  the  cilia  of  a  ciliated  epithelium-cell. 

The  spermatozoa  are  developed  from  the  small  cells  or  spermato- 
blasts which  form  the  innermost  strata  of  the  seminal  epithelium,  and 
are  themselves  produced  by  the  division  of  the  large  cells  of  the  second 
layer.  The  nucleus  of  the  spermatoblast  forms  the  head  of  the  sperma- 
tozoon, while  the  protoplasm  forms  first  the  middle-piece  and  subse- 
quently the  tail ;  but  a  portion  of  the  protoplasm  of  each  spermato- 
blast containing  a  number  of  small  darkly  staining  particles  (seminal 
granules)  appears  always  to  become  detached  and  disintegrated  before 
the  spermatozoon  is  fully  mature. 


17S 


THE  ESSENTIALS   OF   HISTOLOGY 


LESSON  XXXV. 

GENERATIVE  ORGANS   OF  THE   FEMALE,   AND  MAMMARY    ' 

GLANDS. 

1.  Sections  of  the  ovary  of  the  rabbit.  Study  the  sections  with  the  low 
power,  observing  the  small  and  large  Graafian  vesicles,  each  enclosing  an 
v>vum,  scattered  through  the  stroma.  Measure  some  Graafian  vesicles  of 
different  sizes  ;  make  a  general  sketch  of  a  section  under  the  low  power. 
Then  sketch  carefully  two  or  more  of  the  Graafian  vesicles  with  their  contents. 

2.  Sections  across  the  Fallopian  tube.  Sketch  a  section  under  the  low  power. 

3.  Section  across  the  body  of  the  uterus.  Observe  with  the  naked  eye 
the  thickness  of  the  muscular  and  mucous  coats  respectively.  Notice  the 
ciliated  columnar  epithelium  lining  the  organ  and  extending  into  the  glands 
of  the  mucous  membrane.     Draw  a  part  of  the  section  under  the  low  power. 

4.  Sections  of  the  mammary  gland  from  an  animal  killed  during  lactation. 
Notice  the  fat-globules  in  the  alveoli  and  also  in  the  alveolar  cells.  Draw  an 
alveolus  under  the  high  power. 


The  ovary  is  a  small  solid  organ,  composed  of  a  stroma  of  fibrous 
tissue,  with  many  spindle-shaped  cells,  and  also  containing,  especially 
near  its  attachment  to  the  broad  ligament,  a  large  number  of  plain 


Y^£ 


Fig.  215. — Section  of  the  ovary  of  the  cat.  f 

1,  outer  covering  and  free  border  of  the  ovary  ;  1'.  attached  border  ;  2,  the  central  ovarian 
stroma,  presenting  a  fibrous  and  vascular  structure  ;  3,  peripheral  stroma  ;  4.  blood- 
vessels; 5,  Graafian  follicle?  in  their  earliest  stages  lying  near  the  surface:  6,  7,  8,  more 
advanced  follicles  which  are  embedded  more  deeply  in  the  stroma  ;  9,  an  almost  mature 
follicle  containing  the  ovum  in  its  deepest  part ;  9',  a  follicle  from  which  the  ovum  lias 
accidentally  escaped  ;  10,  corpus  luteum. 


GENERATIVE  ORGANS  OF  THE  FEMALE 


170 


muscular  fibres.  It  is  covered  by  a  layer  of  small  columnar  epithelium- 
cells  (germinal  epithelium,  fig.  21G,  a),  between  which  are  here  and 
there  to  be  seen  a  few  larger  spheroidal  cells,  with  large  round  nuclei 
(primitive  ova,  fig.  218,  c).  In  the  young  subject  the  epithelium  may 
occasionally  dip  down  into  the  subjacent  stroma. 

The  stroma  is  beset  with  vesicles  of  different  sizes,  the  smallest 


Fig.  216. — Section  of  the  ovary  of  an  adult  hitch.     V 

a,  germ-epithelium  :  b,  egg-tubes  ;  c,  c,  small  follicles  ;  •/.  more  b  liele;  e,  discus  pro- 

ligerus  and  ovum  :  /,  second  ovum  in  the  same  follicle  <  this  occurs  but  rarely  i :  g,  outer 
tunic  of  the  follicle;   A.  inner  tunic;   (,  membrana  granulosa;   t,  collapsed  retro 
follicle;  /,  blood-vessels :  >«.  /".  longitudinal  and  transverse  sections  of  tubes  of  the  paro- 
varium :  y,  involuted  portion  of  the  germ-epithelium  of  the  surface  ;  ;,  place  of  the  transi- 
tion from  peritoneal  to  germinal  or  ovarian  epithelium. 


being  near  the  surface  of  the  organ,  the  larger  ones  placed  more  deeply 
in  the  stroma,  although,  as  they  increase  in  size,  they  may  again  tend 
to  approach  the  surface. 

These  vesicles  are  the  Graafian  follicles.     Each  Graafian  follicle 

n2 


180 


THE  ESSENTIALS   OF  HISTOLOGY 


lias  a  proper  wall  of  basement-membrane,  strengthened  by  a  layer 
derived  from  the  stroma,  and  contains  an  ovum,  surrounded  by  a 
number  of  epithelium-cells.  In  the  smallest  follicles  the  ovum  is 
small,  and  the  epithelium  of  the  follicle  is  formed  of  a  single  layer  of 
cells,  which  are  flattened  against  the  ovum.  In  somewhat  larger 
follicles  the  epithelium-cells  are  in  two  layers,  and  these  are  columnar 
in  shape.  In  still  larger  ones,  each  of  these  two  layers  is  formed  of 
several  strata  of  cells,  and  fluid  has  begun  to  collect  between  the 
layers  at  one  part.  Of  the  two  layers,  the  one  which  lines  the  cavity 
of  the  follicle  is  termed  the  membrana  granulosa,  while  the  mass  of 
cells  which  more  immediately  surrounds  the  ovum  is  known  as  the 
discus  proligerus. 

In  the  largest  follicles  the  fluid  has  much  increased  in  amount,  so 
that  the  follicle  has  become  gradually  larger  and  more  tense.  Finally 
it  reaches  the  surface  of  the  ovary,  and  projects  from  that  surface, 
where  it  eventually  bursts,  and  the  liquor  folliculi,  with  its  contained 
ovum,  is  set  free.  This  event  occurs  at  about  the  time  of  menstrua- 
tion.1 


Fig.  217. — Semi-diagrammatic  representation  of  a  mammalian  ovum. 

(Highly  magnified.) 

zp,  zona  pellucida  ;  vi,  vitellus  ;  gv,  germinal  vesicle ;  gs,  germinal  spot. 

The  ova  are  large  spheroidal  cells  (fig.  217).  When  mature,  as  in 
the  largest  Graafian  follicles,  each  ovum  is  surrounded  by  a  thick 
transparent  striated  membrane  (zona  pellucida).  Within  this  is  the 
protoplasm  of  the  cell  (vitellus),  filled  with  fatty  and  albuminous 
granules.  Lying  in  the  vitellus,  generally  eccentrically,  is  the  large 
clear  round  nucleus  (germinal  vesicle),  which  contains  an  intranuclear 
network,  and  usually  one  well-marked  nucleolus  [germinal  spot).  Both 
the  ova  and  the  epithelium  of  the  Graafian  follicles  are  developed 

1  Some  of  the  Graafian  follicles  do  not  burst,  but,  after  attaining  a  certain 
stage  of  maturity,  undergo  a  process  of  retrograde  metamorphosis  and  eventually 
disappear. 


GENERATIVE  ORGANS  OF  THE  FEMALE 


181 


originally  from  the  germinal  epithelium.  In  the  enibryo.  this  forms 
a  thick  layer,  covering  the  fibrous  and  vascular  stroma.  After  a  time 
solid  cords  of  epithelium-cells,  which  in  some  animals  are  partly 
tubular  (ovarian  tubes  of  Pfliiger),  grow  down  into  the  stroma,  whilst 
this  at  the  same  time  grows  into  the  epithelium.  The  cords  presently 
become  broken  up  by  the  ingrowths  of  stroma  into  small  isolated  nests 
of  epithelium-cells,  each  of  which  may  represent  a  Graafian  follicle. 
To  form  the  ova,  some  of  the  germinal  epithelium-cells  become  en- 
larged, and  usually  there  is  one  such  enlarged  cell  hi  each  of  the 
isolated  nests.  The  remaining  cells  form  the  epithelium  of  the  follicle 
(see  fig.  218). 


Fig.  218. — Section'  of  the  ovary  <>f  a  newly  born  child.     (Highly  magnified.) 

a,  ovarian  or  germinal  epithelium  :  b.  formation  of  an  ovarian  tube  ;  c,  c,  primordial  ova  lying 
in  the  germ-epithelium;  <i,  d,  longer  tube  becoming  constricted  so  as  to  form  nests  of 
cells ;  e,  c  larger  nests  ;  /,  distinctly  formed  follicle  with  ovum  and  epithelium ;  g,  g, 
blood-vessels. 

The  stroma  of  the  ovary  contains,  besides  the  spindle-shaped  con- 
nective-tissue cells  and  plain  muscular  fibres  already  mentioned,  a 
number  of  epithelium-like  interstitial  cells,  like  those  found  in  the 
intertubular  tissue  of  the  testis.  They  are  most  abundant  near  the 
hilus.  Corpora  lutea  may  also  be  seen  in  the  stroma.  These  are 
large  yellow  nodules,  which  are  developed  out  of  the  Graafian  follicles 
after  the  ovum  has  become  extruded.  They  consist  of  columns  of 
large  yellowish  cells,  with  intervening  vascular  fibrous  tissue,  which 
converge  to  a  central  strand  of  connective  tissue  occupying  the  axis  of 
the  nodule.  The  columns  of  yellow  cells  are  not  unlike  those  of  the 
cortex  of  the  suprarenal  capsule.  The  cells  are  derived  from  the 
membrana  granulosa  of  the  follicle,  which  becomes  thickened  and 
folded  ;  between  the  folds  connective  tissue  and  blood-vessels  grow  in 
towards   the   centre,   and   in   this  way   the   corpus   luteuni   becomes 


182  THE   ESSENTIALS   OF  HISTOLOGY 

developed.  After  persisting  for  a  time  it  gradually  shrinks  and  disap- 
pears, but  it  becomes  larger  and  remains  longer  persistent  in  the  event 
of  pregnancy  supervening. 

The  Fallopian  tubes  are  chiefly  composed  of  plain  muscular  tissue 
disposed  circularly.  They  are  lined  by  a  mucous  membrane  which  is 
covered  with  ciliated  epithelium.  Externally  they  are  covered  by  a 
serous  coat,  within  which  is  a  thin  layer  of  longitudinal  muscular  fibres 
overlying  the  circular  fibres. 

The  uterus  is  usually  described  as  composed  of  two  parts,  the  body 
and  cervix.    The  wall  of  the  uterus  is  formed  of  the  following  layers : 

1.  A  serous  la yer,  derived  from  the  peritoneum,  which  covers  the 
greater  part  of  the  fundus. 

2.  A  muscular  layer,  which  is  of  considerable  thickness  and  is 
composed  of  plain  muscular  fibres  disposed  hi  two  imperfectly  separated 
strata.  Of  these  the  outer  is  much  the  thinner,  and  its  fibres  are  dis- 
posed partly  longitudinally,  partly  circularly.  The  inner  muscular 
layer,  on  the  other  hand,  is  very  thick  ;  its  fibres  run  in  different  direc- 
tions, and  it  is  prolonged  internally  into  the  deeper  part  of  the  mucous 
membrane,  the  extremities  of  the  uterine  glands  extending  between 
and  amongst  its  fibres.  It  is  imperfectly  separated  from  the  thinner 
external  layer  by  the  ramifications  of  the  larger  blood-vessels,  and 
probably  represents  a  much-hypertrophied  muscularis  mucosas. 

3.  A  mucous  membrane,  which  is  very  thick  and  is  composed  of  soft 
connective  tissue  containing  a  large  number  of  spindle-shaped  cells.  It 
contains  long,  simple,  tubular  glands  (fig.  219),  which  take  a  curved  or 
convoluted  course  in  passing  through  the  membrane.  They  are  lined 
by  ciliated  epithelium  continuous  with  that  which  covers  the  inner 
surface  of  the  mucous  membrane.  In  the  cervix  the  mucous  membrane 
is  marked  by  longitudinal  and  oblique  ridges,  and  the  glands  are  shorter 
than  those  of  the  body  of  the  uterus.  Near  the  os  uteri  the  epithelium 
becomes  stratified  and  overlies  vascular  papillae  of  the  corium.  The 
mucous  membrane  is  exceedingly  vascular,  and  it  also  contains  a  large 
number  of  lymphatic  vessels. 

At  each  menstrual  period  the  greater  part  of  the  mucous  membrane 
of  the  body  undergoes  a  process  of  disintegration  accompanied  by  an 
escape  of  blood  from  the  capillaries  of  the  membrane.  This  is  suc- 
ceeded by  a  rapid  renewal  of  the  membrane.  Should  gestation  super- 
vene, the  process  of  renewal  results  in  the  formation  of  a  greatly 
thickened  mucous  membrane,  with  long  convoluted  glands,  which  is 
then  known  as  the  decidua. 

The  mammary  glands  are  compound  racemose  glands  which  open 
by  numerous  ducts  upon  the  apex  of  the  nipple.  The  ducts  are  dilati  d 
into  small  reservoirs  just  before  reaching  the  nipple.  If  traced  back- 
wnrds,  they  are  found  as  in  other  compound  racemose  glands  to  com- 
mence in  groups  of  saccular  alveoli.  The  walls  of  the  ducts  and  alveoli 
are  formed  of  a  basement-membrane  lined  by  a  simple  layer  of  flattened 
epithelium  (fig.  220,  A).     But  during  lactation,  when  the  gland  is  in 


GENERATIVE  ORGAN'S  OF  THE  FEMALE 


183 


r-.  V 


<5_il| 


I,';}  ,'•'■'  ■■ 


Fig.  219. — Sectioh  of 
the  mucous  mem- 
brane of  the  ute- 
rus fr>>m  near 
the    fundus. 

o,  epithelium  of  inner 
surface;  6,  V,  uterine 
glands;  c,interglandulai 

connective    ti>-ue ;    d, 
muscular  tissue. 


184 


THE   ESSENTIALS   OF  HISTOLOGY 


activity,  the  cells  of  the  alveoli  become  much  enlarged  and  of  a  columnar 
shape,  and  fatty  globules  become  formed  within  them  (B).  These  fatty 
globules  appear  to  become  set  free  by  the  breaking  down  of  the  inner  part 
of  the  cell,  the  protoplasm  of  the  cells  becoming  partially  dissolved  and 


Fig.  220. — Alveoli  of  the  mammary  gland  of  the  bitch  under  different 
conditions  of  activity. 

A,  section  through  the  middle  of  two  alveoli  at  the  commencement  of  lactation,  the 
epithelium-cells  being  seen  in  profile ;  £,  an  alveolus  in  full  secretory  activity. 


forming  the  proteid  substances  of  the  milk.  According  to  some  authors, 
lymph-corpuscles  may  also  carry  fat  into  the  alveoli  and  there  become 
disintegrated.  At  the  commencement  of  lactation  this  disintegration 
is  imperfect,  so  that  numerous  cells  containing  fat-particles  appear  hi 
the  secretion  [colostrum  corpuscles). 


185 


LESSON  XXXVI. 

STRUCTURE   OF  THE   SPINAL   CORD. 

1.  Sections  of  the  spinal  cord  from  the  cervical,  dorsal,  and  lumbar  regions. 

[The  spinal  cord  is  hardened  by  being  immersed  for  about  a  month  in 
bichromate  of  ammonia  solution  (2  per  cent.)  ;  the  sections  are  made  with  a 
freezing  microtome  and  are  stained  with  aniline  blue  black.1] 

Notice  the  relative  extent  of  the  grey  as  compared  with  the  white  matter 
in  the  different  regions  of  the  cord.  In  the  white  matter  the  stained  dots 
are  sections  of  the  axis-cylinders  of  the  longitudinally  disposed  medullated 
nerve-fibres ;  the  tissue  between  the  nerve-fibres  is  neuroglia.  In  the  grey 
matter  the  branched  nerve-cells  are  conspicuous,  lying  m  a  reticular  sub- 
stance which  is  formed  of  neuroglia  together  with  an  interlacement  of  nerve- 
fibres  and  cell-processes. 

Sketch  a  section  from  each  region  under  a  low  power.  Sketch  also  a 
small  portion  of  the  white  substance,  two  or  three  nerve-cells,  and  the  central 
canal  with  its  fining  epithelium  and  surrounding  neuroglia  under  the  high 
power. 

Measure  the  diameter  of  some  of  the  nerve-fibres  in  the  anterior  columns, 
in  the  lateral  columns,  and  in  the  posterior  columns 


The  spinal  cord  is  composed  of  grey  matter  in  the  centre  and  of 
white  matter  externally.  It  is  closely  invested  by  a  layer  of  connective 
tissue  containing  numerous  blood-vessels  (pia  mater),  and  less  closely 
by  two  other  membranes.  One  of  these  is  an  areolar  membrane,  re- 
sembling a  serous  membrane  in  general  structure,  but  non -vascular  and 
more  delicate  in  texture  {arachnoid).  The  other,  which  lines  the 
vertebral  canal,  is  a  strong  fibrous  membrane  known  as  the  dura  mater. 
At  the  middle  of  the  anterior  and  posterior  surfaces  the  pia  mater  dips 
into  the  substance  of  the  cord  in  the  anterior  and  posterior  median  fis- 
sures, so  as  to  divide  it  almost  completely  into  two  lateral  halves.  These 
are,  however,  united  by  an  isthmus  or  bridge,  which  is  composed 
anteriorly  of  transversely  crossing  white  fibres  (white  commissure), 
posteriorly  of  grey  matter  (grey  commissure),  in  the  middle  of  which  is 
a  minute  canal  lined  by  ciliated  epithelium  (central  canal,  fig.  221,  c\. 

Each  lateral  half  of  the  spinal  cord  contains  a  crescent  of  grey 
matter,  which  is  joined  to  the  corresponding  crescent  of  the  opposite 
side  by  the  grey  commissure.     Of  the  two  cornua  of  the  crescent  the 

1  See  Appendix. 


186 


THE   ESSENTIALS   OF   HISTOLOGY 


posterior  is  the  narrower  and  comes  near  the  surface  of  the  cord ; 
opposite  to  it  the  bundles  of  the  posterior  nerve-roots  enter  the  cord. 
The  bundles  of  the  anterior  nerve-roots  enter  the  anterior  cornu. 

The  white  matter  of  each  half  of  the  cord  is  subdivided  by  the 
passage  of  the  nerve-roots  into  the  cornua  into  three  principal  columns 
— anterior,  lateral,  and  posterior.  It  is  composed  of  longitudinally 
coursing  medullated  nerve-fibres,  which  in  stained  sections  appear  as 
clear  circular  areas  with  a  stained  dot,  the  axis-cylinder,  near  the 
middle  (fig.  222). 


Fig.  221.— Section  of  the  spinal  cord  in  the  lower  dorsal  region.    (Cadiat.) 

a,  e,  c,  anterior,  lateral,  and  posterior  columns  ;  s,  6',  anterior  and  posterior  median  fissures. 
a,  6,  e,  cells  of  anterior  cornn ;  d,  posterior  cornu  and  substantia  gelatinosa  of  Rolando; 
e,  central  canal  :  /,  veins :  <j,  anterior  root-bundles  ;  h,  posterior  root-bundles  ;  i,  white 
commissure  ;  J,  grey  commissure  ;  I,  reticular  formation. 


The  medullated  fibres  are  supported  by  a  peculiar  reticular  tissue 
(neuroglial  which  contains  a  number  of  nuclei  embedded  in  it  and 
appears  to  be  composed  of  branched  fibrillated  cells  (neuroglia-cells). 
The  neuroglia  is  accumulated  in  greater  amount  at  the  surface  of  the 
cord  underneath  the  pia  mater  (fig.  222),  and  it  extends  into  the  grey 
matter,  of  which  it  may  be  said  to  form  the  basis,  and  in  which  it  is 
especially  accumulated  at  the  apex  of  the  posterior  cornu  and  around 
the  central  canal  [substantia  gelatinosa  of  Rolando). 


STRUCTURE   OF   THE   SPINAL   CORD 


187 


The  grey  matter,  besides  neuroglia,  consists  of  an  interlacement  of 
nerve-fibres  and  of  the  branching  processes  of  the  nerve-cells  which  are 
embedded  in  it. 


■v-  •  "  • 

•  n 


Fig.  222.=— A  small  portion  of  a  transverse  section  of  the  human  spinal  cord 

IN   THE    REGION    OF    THE    LATERAL    COLUMN,    TO    SHOW    THE    SUPERFICIAL   NEUROGLIA. 

a,  a,  superficial  neuroglia  :  6,  b,  transverse  section  of  part  of  the  lateral  column  of  the  cord,  in 
which  the  dark  points  are  the  axis-cylinders,  and  the  clear  areas  the  medullar;  substance 
of  the  nerve-fibres.  The  superficial  neuroglia  is  seen  to  exhibit  the  appearance  of  a  fine  net- 
work in  which  numerous  nuclei  anil  one  or  two  corpora  amylacea  are  embedded,  and  to 
extend  inwards  among  the  nerve-fibres. 


Disposition  of  the  nerve-fibres  of  the  ickite  columns  in  tracts. — 
The  nerve-fibres  vary  in  size  in  different  parts  of  the  white  columns. 
They  are  smallest  in  the  posterior  columns,  especially  in  that  part 
of  the  posterior  column  which  is  next  the  posterior  median  fissure 
(posterior  median  column),  and  largest  in  the  posterior  part  of  the 
lateral  column,  but  also  of  considerable  size  in  the  anterior  column. 
This  difference  corresponds  in  some  measure  with  the  functions  of  the 
nerve-fibres  in  those  parts  respectively.  Thus  the  posterior  part  of 
the  lateral  column  which  is  characterised  by  the  large  size  of  its  nerve- 
fibres  constitutes  the  tract  along  which  voluntary  motor  impressions 
pass  down  the  spinal  cord  from  the  opposite  side  of  the  brain,  after 
having  crossed  at  the  pyramids  of  the  medulla  oblongata  (crossed 
pyramidal  tract,  fig.  223,  c.p.t.).  The  large  fibres  which  lie  in  the 
anterior  columns  next  to  the  anterior  median  fissure,  and  the  upper 
part  of  the  cord,  belong  to  a  portion  of  the  same  tract  which  has  not 
undergone  decussation  (direct  pyramidal  tract,  d.p.t.).  The  small 
fibres  of  the  posterior  median  column  belong  to  a  tract  which  is  only 
distinct  above  the  middle  of  the  dorsal  region  of  the  cord,  and  is  known 
as  the  tract  of  Goll  (fig.  22::.  g).  The  rest  of  the  posterior  column  is 
termed  the  cuneate  fasciculus,  and  is  chiefly  composed  of  the  fibres 
of  the  posterior  nerve-roots  which  run  for  a  short  distance  in  it  before 
entering  the  grey  matter.  In  the  lateral  column  there  is  another  tract 
which  is  distinct  in  the  cervical  and  dorsal  regions.     This  lies  external 


188 


THE   ESSENTIALS  OF  HISTOLOGY 


to  the  crossed  pyramidal  tract,  and  consists  of  large  fibres  which  pass 
up  into  the  cerebellum  {direct  cerebellar  tract,  c.t.). 


Fig.  223.  —  Diagrammatic  sec- 
tions OF  THE  SPINAL  CORD  AT 
DIFFERENT  PARTS,  TO  SHOW  THE 
CHIEF  LOCALISED  TRACTS  OF 
FIBRES  IX  THE  WHITE  SUB- 
STANCE. (One  and  a  half  times 
the  natural  size.) 

/.  at  the  level  of  the  sixth  cervical 
nerve  ;  //.  of  the  third  dorsal  ;  ///. 
of  the  sixth  dorsal;  IV  of  the 
twelfth  dorsal  :  J",  at  the  level  of  the 
fourth  lumbar,  d.p.t.  direct  or  an- 
terior pyramidal  tracts  :  c.j'.t.  crossed 
or  lateral  pyramidal  tracts;  c.t.  direct 
cerebellar  tract ;  g,  tract  of  Goll. 


d.p.t. 


The  course  of  the  nerve-tracts  in  the  spinal  cord,  and  in  other  parts 
of  the  central  nervous  system,  can  best  be  made  out  by  the  study  of 
sections  of  the  fatal  cord,  for  it  is  found  that  the  development  of  the 
medullary  substance  occurs  sooner  in  some  tracts  than  in  others,  so  that 
it  is  easy  to  make  out  the  distinction  between  them.  Another  method 
consists  in  investigating  the  course  which  is  pursued  by  degenerations 
of  the  nerve-fibres  in  consequence  of  lesions  produced  accidentally  or 
purposely. 

Disposition  of  the  nerve-cells  in  the  grey  matter. — The  nerve-cells 
•which  are  scattered  through  the  grey  matter  are  in  part  disposed  into 
definite  groups.  Thus  there  is  a  group  of  large  multipolar  nerve-cells 
in  the  anterior  cornu  ;  their  axis-cylinder  processes  pass  out  into  the 
anterior  nerve-roots  {column  of  the  anterior  cornu,  fig.  221,  a,  b,  c).  In 
the  middle  dorsal  region  there  is  a  well-marked  group  of  large  rounded 


STRUCTURE   OF  THE   SPINAL   CORD 


189 


nerve-cells  at  the  base  of  the  posterior  cornu  (Clarke's  column). 
Another  group  is  seen  on  the  outer  side  of  the  grey  matter  lying  in  a 
projection  which  is  sometimes  known  as  the  lateral  cornu  (intermedio- 
lateral  tract).  This  also  is  only  distinct  in  the  dorsal  region.  The 
cells  of  tlie  posterior  cornu  are  not  collected  into  a  special  group. 

Course  of  the  nerve-roots  in  the  spinal  cord. — The  anterior  roots 
enter  the  anterior  cornu  in  a  number  of  bundles  (fig.  224,  a,  a).  Some 
of  their  fibres  (i,  l)  are  directly  connected  with  the  nerve-cells  there, 
others  pass  through  the  grey  matter  into  the  posterior  cornu,  others  into 


p.m.f 
Fig.  224. — Diagram  to  il- 
lustrate THE  PROBABLE 
COURSE  TAKEN  BY  THE  FI- 
BRES OF  THE  NERVE-ROOTS 
ON  ENTERING  THE  SPINAL 
CORD. 

a,  a,  two  bundles  of  the  anterior 
root  of  a  nerve ;  1,  1,  some  of 
their  fibres  passing  into  the 
lateral  cells  of  the  anterior 
cornu ;  1',  1',  others  passing 
into  the  mesial  cells  of  the 
same  cornu  ;  2,  2,  fibres  passing 
to  the  lateral  column  of  the 
same  side  without  joining 
nerve-cells  ;  3,  3,  fibres  passing 
towards  the  posterior  cornu ; 
4,  4,  fibres  passing  across  the 
anterior  commissure,  to  enter 
nerve-cells  in  the  anterior  cornu 
of  the  other  side ;  p,  bundle 
of  the  posterior  root ;  p,  I,  fibres 
of  its  lateral  or  external  divi~ii  in 
coming  through  and  around 
the  gelatinous  substance  of 
Rolando ;  some  of  these,  5,  are 
represented  as  becoming  longi- 
tudinal in  the  latter;  others, 
6,  6,  as  passing  toward-  the 
anterior  cornu,  either  directly 
or  after  joining  cells  in  the  posterior  cornu,  and  others,  7,  as  curving  inwards  towards  the  grey 
commissure  ;  p,  to,  fibres  of  the  mesial  or  inner  division,  entering  the  posterior  column  and  then 
becoming  longitudinal ;  //,  m',  fibres  from  a  posterior  root  which  had  joined  the  cord  lower  down 
and  entered  the  posterior  column,  now  passing  into  the  grey  matter  at  the  root  of  the  posterior 
cornu.  Of  these,  8  is  represented  as  entering  Clarke's  column,  9,  as  curving  around  this  and  cours- 
ing to  the  anterior  commissnre,  and  lit  as  passing  towards  the  anterior  cornu.  The  axis-cylinder 
processes  of  the  cells  of  Clarke's  column  are  shown  arching  round,  and  taking  the  direction  of  the 
lateral  column,  tun.f.,  anterior  median  fissure  ;p.mj.,  posterior  median  fissure  ;  c.c,  central  canal; 
S.R-,  substantia  gelatinosa  of  Rolando. 


the  lateral  white  column  of  the  same  side  of  the  cord  (2,  3\  and  others 
again  pass  across  in  the  isthmus  to  the  anterior  cornu  of  the  opposite 
side  U|. 

The  fibres  of  the  posterior  roots  (fig.  224,  p)  chiefly  pass  into  the 
posterior  white  columns,  from  which  after  a  short  course  they  enter 
the  grey  matter  and  are  partly  connected  with  its  cells,  and  partly  pass 
to  the  other  side  of  the  cord.  Some  of  the  fibres  of  the  posterior 
roots  enter  the  posterior  cornu  directly,  and  are  believed  to  be  con- 
nected with  the  scattered  cells  of  that  cornu. 

The  central  canal  of  the  spinal  cord  is  lined  by  columnar  ciliated 
epithelium-cells,  which  are  surrounded  by  a  quantity  of  neuroglia. 


100 


THE   ESSENTIALS   OF   HISTOLOGY 


The  cells  are  best  seen  in  the  spinal  cord  of  animals  and  in  the  child  ; 
in  the  human  adult  they  have  frequently  become  proliferated,  and  their 
cilia  are  no  longer  visible. 

Characters  of  the  spinal  cord  in  the  several  regions  (fig.  225). 

In  the  cervical  region  the  white  matter,  especially  that  of  the  lateral 


Fig.  225. — Transverse  sections  of  the  spinal  cord  at  different  levels. 
(Twice  the  natural  size.) 

The  letters  and  numbers  indicate  the  position  of  each  section  ;  Ca.  at  level  of  coccygeal  nerve  ; 
Sac.  4  of  4tb  sacral  ;  L3  of  3rd  lumbar,  and  so  on.  The  grey  substance  is  shaded  dark,  and 
the  nerve-cells  within  it  are  indicated  by  dots. 

columns,  occurs  in  largest  proportion.  The  grey  matter,  especially  in 
the  cervical  enlargement,  is  in  considerable  amount  (C  5),  and  it  en- 
croaches in  the  form  of  a  network  upon  the  adjacent  part  of  the  lateral 
white  column.  The  anterior  cornua  are  thick  and  the  posterior  slender. 
The  posterior  median  column  is  distinctly  marked  off. 


STRUCTURE   OF   THE   SPINAL   CORD  191 

In  the  dorsal  region  the  grey  matter  is  small  in  amount,  and  both 
cornua  are  slender  (D  5).  The  whole  cord  is  smaller  in  diameter  than 
either  in  the  cervical  or  lumbar  region.  The  column  of  nerve-cells 
known  as  Clarke's  column,  and  the  intermedio-lateral  tract,  are  well 
marked. 

In  the  lumbar  region  the  crescents  of  grey  matter  are  very  thick, 
and  the  white  substance,  especially  the  lateral  columns,  relatively  small 
in  amount  (L  5).  The  isthmus  lies  nearly  in  the  centre  of  the  cord, 
whereas  in  the  cervical  and  dorsal  regions  it  is  nearer  the  anterior 
surface.     The  posterior  median  columns  are  not  seen. 

In  the  part  of  the  spinal  cord  from  which  the  sacral  and  coccygeal 
nerve-roots  take  origin  the  grey  matter  largely  preponderates,  the 
crescents  forming  thick  irregular  masses,  and  the  grey  isthmus  being 
also  of  considerable  thickness. 


192 


THE  ESSENTIALS  OF  HISTOLOGY 


LESSON  XXXVII. 

THE   MEDULLA   OBLONGATA,  PONS,   AND   MESENCEPHALON. 

1.  Sections  of  the  medulla  oblongata  made,  (a)  at  the  level  of  the  decussation 
of  the  pyramids,  (b)  opposite  the  middle  of  the  olivary  body,  and  (c)  just 
above  the  olivary  body. 

2.  Section  through  the  middle  of  the  pons  Varolii. 

3.  Sections  across  the  region  of  the  corpora  quadrigemina,  one  at  the  level 
of  the  inferior,  the  other  at  the  level  of  the  superior,  pair. 

In  all  the  above  sections  sketch  under  a  low  power  the  general  arrange- 
ment of  the  grey  and  white  matter,  inserting  the  positions  of  the  chief  groups 
of  nerve-cells. 

[The  tissue  is  hardened  and  the  sections  are  prepared,  stained,  and 
mounted  in  the  same  way  as  the  spinal  cord.] 


The  structure  of  the  medulla  oblongata  can  best  be  made  out  by 
the  study  of  a  series  of  sections  taken  from  below  upwards,  and  by 
tracing  in  these  the  changes  which  occur  in  the  constituent  parts  of 
the  spinal  cord,  taking  note  at  the  same  time  of  any  parts  which  may 
be  superadded. 

A  section  through  the  region  of  the  decussation  of  the  pyramids 
(fig.  226)  has  much  the  same  form  as  a  section  through  the  upper  part 


ft   fg 


Fig.  226. — Section  of  the  me- 
dulla OBLONGATA  AT  THE 
MIDDLE  OF  THE  DECUSSATION 
OF  THE  PYRAMIDS. 

anterior,  /.  p.  posterior  fissure ; 
a.]:  pyramid  ;  a,  remains  of  part  of 
anterior  cornu,  separated  by  the 
crossing  bundles  from  the  rest  of  the 
grey  matter;  I,  continuation  of 
lateral  column  of  cord  ;  R,  continua- 
tion of  substantia  gelatinosa  of  Ro- 
lando ;  p.c.  continuation  of  posterior 
teomu  of  grey  matter  ;  /.</.  funiculus 
rracilis. 


of  the  spinal  cord,  and  most  of  the  structures  of  the  cord  can  be  easily 
recognised.  A  considerable  alteration  of  the  grey  matter  is,  however, 
produced  by  the  passage  of  the  large  bundles  of  the  crossed  pyramidal 


STRUCTURE   OF  THE   MEDULLA   OBLONGATA 


193 


tract  (p)  from  the  lateral  column  of  the  spinal  cord  on  each  side 
through  the  root  of  the  anterior  cornu  and  across  the  anterior  median 
fissure  to  the  opposite  anterior  column  of  the  medulla,  where,  together 
with  the  fibres  of  the  direct  pyramidal  tract,  they  constitute  the  promi- 
nent mass  of  white  fibres  which  is  seen  on  the  front  of  the  medulla 
on  each  side  of  the  middle  line,,  and  is  known  as  the  pyramid.  By  this 
passage  of  fibres  through  the  grey  matter  the  tip  of  the  anterior 
cornu  {a)  is  cut  off  from  the  rest  and  becomes  pushed  as  it  were  to 
the  side ;  in  sections  a  little  higher  up  it  appears  as  an  isolated  mass 
of  grey  matter  which  is  known  as  the  lateral  nucleus  (fig.  22,  n.l.) 

A  change  also  occurs  in  the  posterior  cornu  in  consequence  of  the 
increased  development  of  the  posterior  median  and  cuneate  fasciculi. 
This  causes  the  posterior  cornu  (fig.  22G,  p  c)  to  be  pushed  towards  the 
side,  the  V  which  they  form  with  one  another  being  thus  opened  out ; 
at  the  same  time  the  tip  of  the  cornu  swells  out  and  causes  a  prominence 
upon  the  surface  of  the  medulla,  which  is  known  as  the  tubercle  of  Rolando 
(11).  Grey  matter  also  soon  becomes  formed  within  the  upward  pro- 
longations of  the  posterior  median  column  and  of  the  cuneate  fasciculus 


Fig.  227. — Section  of  the  medulla 
oblongata    ix    the    region    of 

Till:  SUPERIOR  PYRAMIDAL  DECUS- 
SATION. 

a.m./.  anterior  median  fissure;  /.a. 
superficial  arciforin  fibres  emerging 
from  the  fissure ;  py,  pyramid;  n.ar. 
nucleus  of  the  arciform  fibres;  /.a'. 
deep  arciform  fibres  becoming  super- 
ficial :  o,  lower  end  of  olivary  nucleus  ; 
o\  accessory  olivary  nucleus;  /,./.  nu- 
cleus lateralis;  />.  formatio  reticu- 
laris :  r'.n  -.  arciform  fibres  proceeding 
from  formatio  reticularis;  <i.  substantia 
gelatinosa  ,,t  Rolando;  a.V,  ascending 
r>»it  i,i'  fifth  nerve;  «.<■.  nucleus  cunea- 
tus;  it. c.  external  cuneate  nucleus; 
/.,-.  funiculus  cuneatus :  ».,/.  nucleus 
gracilis;/.?,  funiculus  gracilis;  p.mf. 
rior  median  fissure;  c.c.  central 
canal  surrounded  by  grey  matter,  in 
whic-li  are,  n.XI.  nucleus  of  the  spinal 
accessory,  and  n.XII.  nucleus  of  the 
hypoglossal;  s.d.  superior  pyramidal 
nation. 


nM. — | 


am./ 


(fig.  227,  n.g.,  n.c.),  but  most  of  the  grey  matter  of  the  cornu  becomes 
broken  up.  by  the  passage  of  bundles  of  nerve-fibres  through  it,  into  a 
reticular  formation  (f.r),  the  production  of  which  is  already  foreshadowed 
in  the  upper  part  of  the  spinal  cord.  The  central  canal  of  the  spinal  cord 
is  still  seen  in  the  lower  part  of  the  medulla  oblongata  (c.  c),  but  it  comes 
nearer  to  the  posterior  median  fissure.  The  grey  matter  which  sur- 
rounds it  contains  two  well-marked  groups  of  nerve-cells  ;  the  anterior 
of  these  is  the  nucleus  of  the  hypoglossal  or  twelfth  nerve  (n.  \u.  i,  the 
posterior  that  of  the  spinal  accessory  or  eleventh  i  u.  xi.  I.  Instead  of  the 

o 


194 


THE   ESSENTIALS   OF  HISTOLOGY 


comparatively  narrow  isthmus  which  joins  the  two  halves  of  the  spinal 
cord,  a  broad  raphe  now  makes  its  appearance  ;  this  is  formed  of 
obliquely  and  antero-posteriorly  coursing  fibres,  together  with  some 
grey  matter  containing  nerve-cells. 

In  a  section  at  about  the  middle  of  an  olivary  body  (fig.  228),  it 
will  be  seen  that  a  marked  change  has  been  produced  in  the  form  of 
the  medulla  and  the  arrangement  of  its  grey  matter,  by  the  opening 
out  of  the  central  canal  into  the  fourth  ventricle.  This  causes  the  grey 
matter  which  below  surrounded  the  central  canal  to  be  now  spread 


•vM  nX't 

nX  f.s. 


p   n.a 


Fig.  228. — Section  of  the  me- 
dulla OBLONGATA  AT  ABOUT 
THE  MIDDLE  OF  THE  OLIVARY 
BODY,      i 

f.l.n.  anterior  median  fissure ;  n.a): 
nucleus  axciformis;  p,  pyramid; 
XII.  bundle  of  hypoglossal  nerve 
emerging  from  the  surface  ;  at  b  it 
is  seen  coursing  between  the  pyra- 
mid and  the  olivary  nucleus,  o ; 
f.a.e.  external  arciform  fibres :  n.l. 
nucleus  lateralis  ;  «,  arciform  fibres 
passing  towards  restiform  body 
partly  through  the  substantia 
tiuosa.  ;/.  partly  superficial  to  tbe 
ascending  root  of  the  fifth  nerve, 
o.V. ;  X,  bundle  of  vagus  root, 
emerging  \f.r.  formatio  reticularis  ; 
c.r.  corpus  restiforme,  beginning  to 
be  formed,  chiefly  by  arciform  fibre-. 
superficial  and  deep  :  n.c.  nucleus 
cuneatus;  n.g.  nucleus  gracilis; 
t.  attachment  of  the  ligula;  /.s. 
funiculus  solitarius ;  n.X.  n.X'. 
two  parts  of  the  vagus  nucli  as; 
n.XII.  hypoglossal  nucleus:  i,.t. 
nucleus  of  the  funiculus  teres  ; 
n.am.  nucleus  ambiguus ;  /•,  r< 
A,  continuation  of  anterior  column 
of  cord :  o',  o",  accessory  olivary 
nuclei ;  olivary  nucleus ;  p.o.l.  pe- 
duuculus  olivaa. 


out  at  the  floor  of  that  ventricle,  and  the  collections  of  nerve-cells  from 
which  the  hypoglossal  and  spinal  accessory  nerves  respectively  arose 
now,  therefore,  lie  in  a  corresponding  situation.  At  this  level,  how- 
ever, the  outer  group  which  corresponds  with  the  nucleus  of  the  spinal 
accessory  in  the  lower  part  of  the  medulla  has  become  the  nucleus  of 
the  vagus  or  tenth  nerve.  The  nerve-bundles  of  the  roots  of  these 
nerves  can  be  seen  in  the  sections  coursing  through  the  thickness  of 
the  medulla  and  emerging,  those  of  the  hypoglossal  (ay/.)  just  outside 
the  pyramids,  those  of  the  spinal  accessory  and  vagus  (x.)  at  the  side 
of  the  medulla.  The  two  sets  of  emerging  fibres  thus  appear  to  sub- 
divide each  lateral  half  of  the  medulla  into  three  areas — a  posterior,  a 
middle,  and  an  anterior.  Of  these  the  posterior  is  chiefly  occupied  by 
the  grey  matter  of  the  floor  of  the  fourth  ventricle,  and,  with  fibres 
which  are  passing  obliquely  upwards  and  outwards  towards  the  cere- 
bellum, forming  its  inferior  eras  (restiform  body,  c.r.) ;  and  in  addition 
there  is  the  continuation  upwards  of  the  portions  of  grey  matter  forming 
the  nuclei  of  the  funiculus  gracilis  (n.g.),  of  the  funiculus  cuneatus 


THE   MEDULLA   OBLONGATA 


195 


(nx. },  and  of  the  tubercle  of  Eolaudo  {g).  The  anterior  or  mesial  area 
is  occupied  in  front  by  the  pyramid  [p),  and  behind  this  by  a  reticular 
formation  (reticularis  alba,  A)  composed  of  longitudinally  coursing 
bundles  of  fibres  interlaced  with  fibres  that  are  passing  obliquely  from 
the  opposite  side,  through  the  raphe,  towards  the  restiform  body  (fig. 
229,  r.a.).  The  middle  area,  which  lies  between  the  issuing  bundles 
of  the  two  sets  of  *nerve-roots,  consists  in  its  deeper  part  of  a  similar 


XII  r.a. 

Fig.  229. — Part  of  the  reticular  formation  <iv  the  medulla  oblongata. 

r.a.  reticularis  alba  :  /■.</.  reticularis  grisea :  between  them  a  root-bundle  of  the  hypoglossal 
(  XII. ).  The  longitudinal  fibres  of  the  reticular  formation  are  out  across  :  the  transversely 
coursing  fibres  are  internal  arcuate  fibres,  passing  on  the  right  of  the  figure  towards  the 
raphe. 

reticular  formation  (fig.  228,  fr),  but  with  more  grey  matter  and 
nerve-cells  [retictda/ris  grisea,  fig.  229,  r.g.)  Superficially  there  is 
developed  within  it  a  peculiar  wavy  lamina  of  grey  matter  containing  a 
large  number  of  small  nerve-cells;  this  is  the  nucleus  of  the  olivary 
bochi  (fig.  228,  o). 

The  floor  of  the  fourth  ventricle  is  covered  by  a  layer  of  ciliated 
epithelium-cells,  continuous  below  with  those  lining  the  central  canal, 
and  above,  through  the  Sylvian  aqueduct,  with  the  epithelium  of  the 

o2 


196 


THE   ESSENTIALS  OF  HISTOLOGY 


third  and  lateral  ventricles.  The  fourth  ventricle  is  roofed  over  by  a 
thin  layer  of  pia  mater,  with  projecting  choroid  plexuses,  the  under 
surface  of  which  is  covered  by  a  thin  epithelial  layer  continuous  at  the 
side  with  the  ciliated  epithelium  of  the  floor. 

A  section  taken  just  above  the  level  of  the  olivary  "prominence  will 
still  show  very  much  the  same  form  and  structural  arrangements  as 
that  just  described.  The  nucleus  of  the  hypoglossal  (fig.  230,  n.  XII.) 
is  still  visible  in  the  grey  matter  of  the  floor  of  the  ventricle,  but  the 
nerve  which  is  now  seen  arising  from  the  outer  part  of  that  grey 
matter  is  the  eighth  or  auditory  i  VIII. ),  the  bundles  of  which,  as  they 
leave  the  medulla,  enbrace  the  inferior  crus  of  the  cerebellum  I 
which  is  now  passing  into  that  organ.     The  reticular  formation  still 


nYIIIrj 


nJffl 


Fig.  230. — Transverse  section  of  the  upper  part  of  the  medulla 
oblongata.    | 

py,  pyramid  ;  o,  olivary  nucleus ;  Y.a.  ascending  root  of  the  fifth  nerve ;  ¥111.  inferior  (pos- 
terior; root  of  the  auditor;  nerve,  formed  of  two  parts,  a.  (striae  acusticse),  and  b,  which 
enclose  the  restiform  body,  c.r. ;  n. VI II. p.  principal  nucleus  of  the  auditory  nerve; 
n.VIII.ac.  accessory  nucleus;  g,  ganglion-cells  in  the  root;  n./J.  nucleus  of  the  funiculus 
teres  ;  n.XII.  nucleus  of  the  hypoglossal ;  r,  raphe. 


occupies  the  greater  part  of  each  lateral  half  of  the  medulla  between 
the  grey  matter  at  the  floor  of  the  fourth  ventricle  and  the  pyramids 
(py),  and  a  small  portion  of  the  olivary  nucleus  (6)  may  still  be  seen, 
as  may  also  the  upward  continuation  of  the  grey  matter  of  the  tubercle 
of  Eolando ;  this  is  intimately  connected  with  some  well-marked 
bundles  of  nerve-fibres,  which  are  passing  up  to  the  pons  to  join  even- 
tually the  root  of  the  fifth  nerve  |  Va). 

A  section  through  the  middle  of  the  pons  Varolii  (fig.  231 1  shows 
very  much  the  same  arrangement  of  grey  and  white  matter  as  that 


STRUCTURE   OF   THE   PONS   VAROLII 


197 


which  is  met  with  at  the  upper  part  of  the  medulla,  but  the  general 
appearance  of  the  section  is  much  modified  by  the  presence  of  a 
large  number  of  transversely  coursing  bundles  of  nerve-fibres  which 
are  passing  from  one  hemisphere  of  the  cerebellum  to  the  other. 
Intermingled  with  these  bundles  is  a  considerable  amount  of  grey 
matter.  The  continuation  upwards  of  the  pyramids  of  the  medulla 
(py)  is  embedded  between  these  transverse  bundles  and  separated 
by  them  froru  the  reticular  formation.     The   olivary  nucleus  is  no 


Fig.  231. — Section  across  the  pons  at  about  the  middle  of  the  fourth 

VENTRICLE,      f 

py,  pyramid-bundle?  continued  up  from  the  medulla  ;  po,  transverse  fibre?  of  the  pons  passing 
from  the  middle  cru-  of  the  cerebellum,  before  (po  )  and  behind  (po1)  the  chief  pyramid 
bundles  ;  t,  deeper  fibres  of  the  same  set.  constituting  the  trapezium  ;  the  grey  "matter 
between  the  transverse  fibres  is  not  represented  either  in  this  or  in  the  two  following' 
figure-:  r.  raphe;  o.s.  superior  olivary  nnclens;  a.V.  bundles  of  the  ascending  root  of 
the  fifth  nerve,  enclosed  by  a  prolongation  of  the  grey  substance  of  Rolando  ;  VI.  the  sixth 
nerve  :  n.YI.  its  nucleus  ;  VII.  the  facial  nerve  :  Vila,  intermediate  portion  of  tl 
nerve  :  n.  VII.  its  nnclens  :  VIII.  anterior  <  superior )  root  of  the  auditory  nerve  ;  n.  VII J. 
part  of  its  outer  or  anterior  (superior)  nucleus  ;  r.  section  of  a  vein. 


longer  seen,  but  there  are  one  or  two  small  collections  of  grey  matter 
which  lie  in  the  antero-lateral  part  of  the  reticular  formation  and  are 
known  as  the  superior  olivary  nucleus  \o.s.)  The  nerves  which  take 
origin  from  the  grey  matter  of  this  region  are  part  of  the  eighth,  the 
seventh,  the  sixth,  and  somewhat  higher  up  the  fifth  cranial  nerves 
( see  figs.  231 ,  232 ) .  Of  these  the  eighth  and  fifth  take  origin  from  groups 
of  nerve-cells  which  occupy  the  grey  matter  opposite  the  external  border 
of  the  floor  of  the  ventricle  ;  the  sixth  from  a  group  which  is  placed  also 


193 


THE   ESSENTIALS  OF   HISTOLOGY 


Fig.  232. — Oblique  section 
op  the  pons  along  the 
link  of   exit  traversed 

I'.Y    THE    FIFTH    NERVE.       f 

The  section  passes  through  the 
lower  part  of  the  motor  nu- 
cleus (  ii'v)  from  which  a  bundle 
of  fibres  of  the  motor  root  is 
seen  passing,  V  ;  a  part  of  the 
upper  sensory  nucleus  (n»)  is 
also  shown  in  the  section  in  the 
form  of  a  number  of  small  iso- 
lated portions  of  grey  matter. 
Amongst  these  are  a  few 
bundles  of  the  ascending  root 
cut  across,  but  most  of  these 
have  already  become  diverted 
outwards  to  join  and  assist  in 
forming  the  issuing  part  of  the 
main  or  sensory  root,  V;  I, 
small  longitudinal  bundle  of 
fibres  near  the  median  sul- 
cus (m.s.),  passing  outwards 
to  join  the  root  of  the  fifth 
nerve ;  />.  formatio  reticu- 
laris ;  r,  raphe ;  s.f,  substan- 
tia ferruginea. 


Fig.  233. — Transverse  section  through  the  upper  part  of  the  pons. 
more  than  twice  the  natural  .size.)1 

p,  transverse  fibres  of  the  pons  ;  py,  py.  bundles  of  the  pyramids  :  a,  boundary  line  between 
the  tegmental  part  of  the  pons  and  its  ventral  part ;  /'.  oblique  fibres  of  the  fillet,  passing 
towards  LP.  longitudinal  fibres  of  the  fillet;  /'./-.  formatio  reticularis:  p.l.  posterior 
longitudinal  bundle  :  i.c.p.  superior  cerebellar  peduncle:  cm.  superior  medullary  velum  : 
b,  grey  matter  of  tho  lingula;  c  4,  fourth  ventricle  :  in  the  grey  matter  which  bound*  it 
laterally  are  seen,  <'.!'.  the  descending  root  of  the  fifth  nerve,  with  its  nucleus. ,«./.  sub- 
stantia ferruginea,  ij.c.  group  of  cells  continuous  with  the  nucleus  of  the  aqueduct. 


I  The  details  of  this  and  of  several  of  the  preceding  figures  are  filled  in  under  a  somewhat 
higher  magnifying  power  than  that  used  for  tracing  the  outlines. 


STRUCTURE  OF  THE  MESENCEPHALON 


199 


in  the  grey  matter  of  the  floor  of  the  ventricle  but  nearer  the  middle  line, 
and  the  seventh  from  a  nucleus  which  lies  in  the  formatio  reticularis, 
and  from  which  the  fibres  of  the  nerve  pass  backwards  to  the  floor  of  the 
ventricle,  then  longitudinally  upwards  for  a  short  distance,  finally 
bending  forwards  and  downwards  and  emerging  between  the  transverse 
fibres  at  the  sides  of  the  pons. 

At  the  upper  part  of  the  pons  (fig.  233)  the  fourth  ventricle  narrows 
considerably  towards  the  Sylvian  aqueduct,  and  behind  and  on  either 


Fig.  234. — Sections  through  the  origin  of  the  fourth  nerve.    | 

A,  transverse  section  at  the  place  of  emergence  of  the  nerve-fibres.  B,  oblique  section 
carried  along  the  course  of  the  bundles  from  the  nucleus  of  origin  to  the  place  of  emer- 
gence. Aq,  Sylvian  aqueduct,  with  its  surrounding  grey  matter;  IV.  the  nerve-bundles 
emerging;  IV.  decussation  of  the  nerves  of  the  two  sides;  IV".  a  round  bundle  passing 
downwards  by  the  side  of  the  aqueduct  to  emerge  a  little  lower  down  ;  n.lV.  nucleus  of 
the  fourth  nerve.  /,  fillet  ;  s.e.p.,  superior  cerebellar  peduncle;  d.Y.  descending  root  of 
the  fifth  nerve ;  pi,  posterior  longitudinal  bundle  ;  r,  raphe. 

side  of  it  two  considerable  masses  of  longitudinal  white  fibres  make  their 
appearance.  These  are  the  superior  crura  of  the  cerebellum  (s.c. p.), 
and  they  tend  as  they  pass  upwards  gradually  to  approach  the  middle 
line  (fig.  234  A),  across  which  in  the  region  of  the  posterior  pair  of  the 
corpora  quadrigemina  they  pass,  decussating  with  one  another,  to  the 
formatio  reticularis  of  the  opposite  side  (fig.  235,  A). 


Fig.  235. — Outline  of  two  sections  across  the  mesencephalon.    (Natural  size.") 

A,  through  the  middle  of  the  inferior  corpora  quadrigemina.  B,  through  the  middle  of  the 
superior  corpora  quadrigemina.  cr.  crusta ;  s.n.  substantia  nigra ;  t,  tegmentum ;  s, 
Sylvian  aqueduct,  with  its  surrounding  grey  matter ;  e.q.  erey  matter  of  the  corpora  qua- 
drigemina ;  l.g.  lateral  groove  :  pj.  posterior  longitudinal  bundle  ;  d.V.  descending  root  of 
the  fifth  nerve  ;  i.e.p.  superior  cerebellar  peduncle  :  /'.  fillet;  n.TII.  its  nucleus ;  ///.  third 
nerve.    The  dotted  circle  in  B  indicates  the  situation  of  the  tegmental  nucleus. 

Iii  sections  across  the  mesencephalon  (fig.  235),  the  upward  con- 
tinuity of  the  parts  which  have  thus  been  described  in  the  lower  parts 
of  the  nerve-centres,  can  still  hi  great  measure  be  traced. 


200  THE   ESSENTIALS   OF   HISTOLOGY 

The  Sylvian  aqueduct  (s),  with  its  lining  of  ciliated  epithelium,  re- 
presents the  central  canal  of  the  cord  and  the  fourth  ventricle  of  the 
medulla.  In  the  grey  matter  which  surrounds  it  {central  grey  matter) 
there  is  seen  in  all  sections  of  the  region  a  group  of  large  nerve-cells 
lying  anteriorly  on  each  side  of  the  middle  line,  close  to  the  reticular 
formation.  From  this  group  the  root-bundles  of  the  fourth  nerve  arise 
at  the  lower  part  of  the  mesencephalon  and  pass  obliquely  backwards 
and  downwards  around  the  central  grey  matter,  decussating  with  those 
of  the  opposite  side  to  emerge  just  above  the  pons  Varolii  (fig.  234). 
Higher  up  the  bundles  of  the  third  nerve  spring  from  the  continuation  of 
the  same  nucleus  (fig.  235,  n.  ///.),  and  these  pass  forwards  and  down- 
wards with  a  curved  course  through  the  reticular  formation,  to  emerge 
at  the  mesial  side  of  the  crusta. 

The  reticular  formation  of  the  pons  is  continued  up  into  the  mes- 
encephalon, and  is  here  known  as  the  tegmentum.  It  is  composed  as 
before  of  longitudinal  and  transverse  bundles  of  fibres  with  much  grey 
matter  intermingled.  The  transverse  fibres  include  the  decussating 
fibres  of  the  superior  crura  of  the  cerebellum  {s.c.j).),  and  the  fibres  of 
the  fillet  (/),  which  are  passing  in  an  oblique  manner  from  the  raphe 
to  the  side  of  the  mesencephalon,  to  reach  eventually  the  grey  matter 
of  the  prominences  of  the  corpora  quadrigemina.  The  pyramid  bundles 
of  the  pons  are  continued  upwards  on  each  side  into  the  crusta  (cr.). 
This  forms  a  mass  of  longitudinally  coursing  bundles  of  fibres  lying  on 
the  ventral  aspect  of  each  half  of  the  mesencephalon,  and  diverging 
above  into  the  internal  capsule  of  the  cerebral  hemisphere.  The  crusta 
is  separated  from  the  tegmentum  by  a  layer  of  grey  matter  containing 
a  number  of  very  deeply  pigmented  nerve-cells  which  give  it  the  name 
of  substantia  nigra  (s.n.)  The  crusta  and  tegmentum,  together  with 
the  intervening  substantia  nigra,  constitute  the  cms  cerebri. 

The  prominences  of  the  corpora  quadrigemina  are  formed  mainly 
of  grey  matter  containing  numerous  small  nerve-cells.  From  each 
a  bundle  of  white  fibres  (brachium)  passes  upwards  and  forwards 
towards  the  geniculate  bodies,  eventually  joining  the  optic  tract  of 
the  same  side.  On  the  other  hand,  each  of  the  prominences  receives 
from  below  fibres  of  the  fillet,  which  are  themselves  traceable  into  the 
posterior  part  of  the  lateral  column  of  the  medulla  oblongata. 


201 


LESSON  XXXVIII. 

STRUCTURE   OF  THE   CEREBELLUM  AND   CEREBRUM. 

1.  Section's  of  the  cerebellum  across  the  direction  of  the  laminae  and  vertical 
to  the  surface. 

2.  Section  across  the  whole  of  one  hemisphere  of  the  cerebrum  of  a 
monkey  or  man,  passing  through  the  middle  of  the  third  ventricle. 

3.  Vertical  sections  of  the  cerebral  cortex,  one  from  the  ascending  frontal 
gyrus,  another  from  the  occipital  lobe,  and  a  third  across  the  hippocarnpal 
gyrus  and  hippocampus. 

4.  Transverse  sections  of  the  olfactory  tract  and  bulb. 

In  all  these  preparations  make  sketches  under  a  low  power  of  the  general 
arrangement  of  the  grey  and  white  matter,  and  also  of  the  nerve-cells  in 
the  grey  matter.     Sketch  some  of  the  details  under  a  high  power. 


The  cerebellum  is  composed  of  a  white  centre,  and  of  a  grey  cortex, 
both  extending  into  all  the  folds  or  lamina?,  so  that  when  the  lamina? 
are  cut  across,  an  appearance  is  presented  of  a  white  arborescence 


Fig.  236. — Section  through  one  of  the  hemispheres  of  the  cerebellum, 
to   show    the   medullary    centre    and    its    prolongations    into  the 

LAMELLA 


covered  superficially  by  grey  matter.  The  white  matter  is  in  largest 
amount  in  the  middle  of  each  cerebellar  hemisphere  (fig.  236).  There 
is  here  present  also  a  peculiar  wavy  lamina  of  grey  matter,  similar  to 
that  in  the  olivary  body,  and  known  as  the  nucleus  dentatus  (ii.d.). 


202 


THE   ESSENTIALS   OF   HISTOLOGY 


Other   isolated  grey  nuclei  He  in  the  white  matter   of  the   middle 
lobe. 

The  grey  matter  of  the  cerebellum  consists  of  two  layers  (fig.  237). 
The  inner  one  (that  next  the  white  centre)  is  composed  of  a  large 
number  of  very  small  nerve-cells  (granule  layer,  d).     The  outer  layer 


Fig.  237. — Section  of  cortex  of  cere- 
bellum. 

a,  pia  mater  ;  b,  external  layer ;  c,  layer  of  cor- 
puscles of  Purkinje ;  d,  inner  or  granule 
layer ;  -e,  medullary  centre. 


Fig.  238. — Processes  op  the  corpus- 
cles OF  PURKINJE,  CONNECTED  BY 
THEIR  FINER  BRANCHES  WITH  COR- 
PUSCLES OF  THE  OUTER  LAYER  OF 
THE    CEREBELLAR    CORTEX.        (Highly 

magnified.) 

a,  a,  processes  of  the  corpuscles  of  Purkinje  ; 
b,  a  branch  from  one  of  them,  which  is  con- 
nected with  two  of  the  corpuscles  of  the 
outer  layer  ;  c,  c,  scattered  branched  cor- 
puscles of  this  layer. 


(b)  is  thicker,  and  is  formed  of  neuroglia,  with  rounded  and  angular 
small  nerve-cells  and  neuroglia-cells  scattered  through  it.  Into  its 
outer  part  processes  of  the  pia  mater  conveying  blood-vessels  pass 
vertically,  and  there  are  also  in  this  part  a  number  of  long  taper- 
ing cells,  somewhat  like  the  Mullerian  fibres  of  the  retina.     Lying 


STRUCTURE    OF   THE   CEREBRAL    CORTEX 


203 


between  the  two  layers  of  the 
grey  matter  is  an  incomplete 
stratum  of  large  flask- shaped 
cells  (cells  of  Purkinje,  c). 
Each  of  these  gives  off  from  its 
base  a  fine  process,  which  be- 
comes the  axis-cylinder  of  one 
of  the  medullated  fibres  of  the 
white  centre,  while  from  the 
opposite  pole  of  the  cell  large 
ramified  processes  spread  out 
into  the  superficial  layer  of 
the  grey  matter,  and  some  of 
these  processes  become  con- 
nected with  its  small  nerve- 
cells  (fig.  238). 

Structure  of  the  cerebrum. 
The  grey  matter  of  the  ce- 
rebral cortex  is  described  as 
being  composed  of  a  number 
of  layers,  but  they  are  not 
sharply  marked  off  from  one 
another.  The  following  are 
usually  distinguished  (fig. 
239). 

1.  Most  externally  a  thin 
stratum  containing  a  few  scat- 
tered cells,  probably  neuro- 
glia-cells.  In  the  most  super- 
ficial part  of  this  layer  imme- 
diately under  the  pia  mater, 
is  a  very  thin  stratum  of 
medullated  nerve-fibres. 

2.  A  layer  of  closely  set 
small  pyramidal  nerve-cells 
several  deep.  This  layer  is 
also  thin. 

3.  A  thick  layer  contain- 
ing larger  and  longer  pyra- 
midal cells  less  closely  set. 
These  cells  are  largest  in  the 
deepest  part  of  the  layer  ;  and 
in  the  region  of  the  motor 
centres  of  the  brain  some  of 
them  are  of  very  large  size, 
and  are  collected  into  small 
groups. 


204 


THE   ESSENTIALS   OF   HISTOLOGY 


4.  A  thin  layer  of  numerous  small  irregular  angular  cells. 

5.  A  rather  thicker  layer  of  small  scattered  cells,  many  of  a  fusi- 
form shape.  This  layer  lies  next  to  the  white  centre.  In  the  island 
of  Eeil  this  stratum  is  considerably  developed,  and  is  somewhat  sepa- 


J   _^- 


' 


[V'/V*     _      '       '    '"      '"!V      ','    ■    ti'ri 


Fig.  240.— Section  across  the  hippocampus  major,  dentate  fissure,  dentate 
fascia  and  fimbria. 

Gh,  part  of  the  gyros  hippocampi  or  uncinate  convolution  ;  Fd,  fascia  dentata,  or  dentate 
convo'ution :  between  them  is  the  dentate  fissure  :  J'i,  fimbria,  composed  of  longitudinal 
fibres  here  cut  across;  1,  2,  medullary  centre  of  the  hippocampal  gyrus  prolonged  around 
the  hippocampus,  //,  as  the  so-called  alveus,  into  the  fimbria;  3,  layer  of  large  pyramidal 
cells ;  4,  their  processes  ( stratum  radiatum ) ;  5.  reticular  neuroglia  (stratum  laciniosum  ) ; 
6,  superficial  medullary  lamina,  involuted  around  the  dentate  fissure  :  *  *,  termination  of 
this  lamina,  the  fibres  here  running  longitudinally  ;  7,  superficial  neuroglia  of  the  fascia 
dentata ;  *,  ring  of  small  cells  within  this  (stratum  granulosum). 

rated  from  the  rest  of  the  grey  matter  by  a  layer  of  white  substance. 
It  is  known  as  the  claustrum. 

From  the  white  centre  bundles  of  medullated  nerve-fibres  pass  in 
vertical  streaks  through  the  deeper  layers  of  the  grey  matter,  to  lose 


STRUCTURE  OF  THE  OLFACTORY  TRACT  AND  BULB  205 

themselves  amongst  the  pyramidal  cells  of  the  more  superficial  layers, 
with  processes  from  which  they  are  probably  continuous. 

In  the  hippocampal  region  a  remarkable  difference  of  structure 
manifests  itself  (fig.  240).  The  superficial  layer  of  neuroglia  and  the 
white  stratum,  which  overlies  it  as  a  thin  band  in  other  parts  of  the 
cortex,  are  in  this  region  both  very  strongly  marked  (5,  6 ),  the  neuroglia 
layer  having  a  very  distinctly  reticular  aspect,  and  being  in  part  beset 
with  small  cells.  All  the  rest  of  the  thickness  of  the  grey  matter 
appears  to  be  mainly  composed  of,  or  at  least  to  contain,  long  conical 
cells  (3,  4),  the  distal  processes  or  apices  of  which  are  prolonged  into 
fibres  which  lose  themselves  in  the  superficial  layer  of  neuroglia.  The 
pyramidal  cells  rest  upon  the  white  centre,  here  known  as  the  atoms  (l), 
which  is  the  part  of  the  hippocampus  seen  within  the  ventricle,  and 
which  is  prolonged  externally  into  the  fimbria  (Fi),  where  its  fibres  be- 
come longitudinal  in  direction. 

In  the  dentate  gyrus  (fascia  dentata,  fig.  240,  Fd)  the  pyramidal 
cells  are  arranged  in  an  irregularly  radiating  manner,  occupying  the 
centre  of  the  convolution,  and  surrounded  by  a  ring  of  closely  packed 
small  cells  (*),  external  to  these  being  the  relatively  thick  layer  of 
superficial  neuroglia  (7). 

The  olfactory  tract  is  an  outgrowth  of  the  brain  which  was  ori- 
ginally hollow,  and  remains  so  in  many  animals  ;  but  in  man  the 
cavity  has  become  obliterated,  and  the  centre  is  occupied  by  neuroglia, 
containing,  however,  no  nerve-cells  (fig.  241).      Outside  the  central 


Fig.  241. — Section  across  the  olfactory  tract. 

neuroglia  lies  the  white  or  medullary  substance,  consisting  of  bundles 
of  longitudinal  white  fibres.  Most  externally  is  a  thin  superficial 
layer  of  neuroglia. 

The  olfactory  bulb  (fig.  242)  has  a  more  complicated  structure. 
Dorsally  there  is  a  flattened  ring  of  longitudinal  white  bundles  enclosing 
neuroglia  (l,  2,  3),  as  in  the  olfactory  tract,  but  below  this  ring  a 
number  of  layers  are  superadded  as  follows  : 

1.  A  granule  layer  (fig.  242,  4),  characterised  by  the  presence  of  a 


206 


THE   ESSENTIALS   OF   HISTOLOGY 


large  number  of  small  nerve-cells  with  reticulating  bundles  of  meclul- 
lated  nerve  fibres  running  between  them. 

2.  An  intermediate  nerve-cell  layer  (6)  consisting  of  neuroglia,  in 
which  small  pyramidal  nerve-cells  are  embedded.  This  layer  is  also 
traversed  by  medullated  nerve-fibres,  and  is  partly  separated  from  the 
granule  layer  by  irregular  clefts  (5). 

3.  The  layer  of  olfactory  glomeruli  (7)  consists  of  rounded  nests  of 
small  ganglion-cells,  which  appear  to  give  origin  to  the  olfactory  nerve- 
fibres.  These  pass  between  the  glomeruli  to  enter  the  close  plexus  of 
non-medullated  nerve-fibres  which  lies  directly  over  the  cribriform  plate. 

4.  This  is  the  layer  of  olfactory  nerve-fibres  (8),  and  from  it 
branches  (*)  pass  directly  downwards  to  the  nasal  fossas. 


Fig.  242.— Section  across  a  part  of  the  olfactory  bulb. 

1,  3.  bundles  of  very  fine  transversely  cut  nerve-fibres,  forming  tbe  flattened  medullary  ring, 
enclosing  the  central  neuroglia,  2;  4,  granule-layer:  5.  loose  tissue  with  irregular  spaces 
(?  lymphatic);  (;.  intermediate  layer;  7,  layer  of  olfactory  glomeruli,  t,  "ft ;  8,  layer  of 
olfactory  nerve-fibres. 


Basal  ganglia. — Besides  the  grey  matter  of  the  cerebral  cortex  the 
cerebral  hemispheres  conceal  in  their  deeper  parts  certain  other  masses 
of  grey  substance  (fig.   243).     The  principal  of  these  are  the  corpus 

striatum  (nucleus  caudatus,  c,  and  nucleus  lenticularis,  str)  and  optic 
thalamus  (th).    Between  them  run  the  bundles  of  white  fibres  which  are 


STRUCTURE   OF   THE   CORPUS   STRIATUM 


207 


passing  upwards  from  the  crus  cerebri,  forming  a  white  lamina  termed 
the  internal  capsule.  Above  the  level  of  these  nuclei  the  internal 
capsule  expands  into  the  medullary  centre  of  the  hemisphere  (see  also 
figs.  244  and  245,  with  their  description). 


Fig.  243. — Frontal  section-  through  the  brain  and  skull  made  whilst 

FROZEN.      h 

c.c.  corpus  callosum  ;  below  its  middle  part  the  septum  lucidum.  and  below  that  again  the 
fornix  ;  L  V,  Lateral  ventricle  :  ih,  thalamus  :  between  the  two  thalaroi  the  third  ventricle 
j-  jeen  :  below  the-  thalamus  is  the  subthalamic  prolongation  of  the  tegmental  region,  and 
below  this  the  prolongation  of  the  crusta  ;  str,  lenticular  nucleus  of  the  corpus  striatum  ; 
c,  caudate  nucleus  of  the  same  ;  between  c.  th,  and  sir,  the  internal  capsule  i~  seen  ;  outside 
tlr  i-  the  thin  grey  band  of  the  claustrum.  and  outside  this  again  the  island  of  Beil  at  the 
bottom  of  the  Sylvian  fissure  :  n.a.  nucleus  amygdala- :  immediately  within  this  is  the  optic 
tract  seen  in  section  ;  p,  pituitary  body  ;  B,  body  of  the  sphenoid  bone  ;  sa,  subarachnoid 
space  ;  v,  villi  of  the  arachnoid. 


The  nucleus  caudatus  of  the  corpus  striatum  is  composed  of  a 
reddish-grey  neuroglia  containing  both  moderately  large  and  small  multi- 
polar nerve-cells.  It  receives  fibres  from  the  part  of  the  internal 
capsule  which  separates  it  from  the  nucleus  lenticularis,  and  next  the 
lateral  ventricle  it  is  covered  by  a  thin  layer  of  neuroglia,  and  over 
this  by  the  epithelium  of  the  cavity. 

The  nucleus  lenticularis,  which  corresponds  in  position  internally 
with  the  island  of  Reil  externally,  is  divided  by  two  white  lamina?  into 
three  zones.  It  is  separated  from  the  nucleus  caudatus  and  optic  thala- 
mus by  the  internal  capsule  (figs.  244,  245,  ic),  which  consists  of  the 
bundles  of  medullary  fibfes  which  are  passing  between  the  white  centre 
of  the  hemisphere  and  the  crus  cerebri ;  it  receives  on  its  inner  side 
many  white  fibres  from  the  capsule,  and  these  impart  to  it  a  radially 
striated  aspect.  Many  of  the  nerve-cells  of  the  nucleus  lenticularis 
contain  yellow  pigment. 


208 


THE   ESSENTIALS   OF  HISTOLOGY 


Fig.  244. — Section  across  the  optic  thalamus  and  corpus  striatum  in  the 
region  of  the  middle  commissure.     (Natural  size.) 

th,  thalamus ;  a,  e,  i,  its  anterior,  external,  and  internal  nuclei  respectively  ;  tc,  its  external 
white  laver ;  m.  c.  middle  commissure ;  v.  3.  third  ventricle  ;  a  small  part  is  also  seen  below 
the  middle  commissure  ;  c.  e.  corpus  callosum  ;  /',  fornix,  separated  from  the  third  ventri- 
cle and  thalamus  by  the  velum  interpositum.  In  the  middle  of  this  are  seen  the  two  veins 
of  Galen  and  the  choroid  plexuses  of  the  third  ventricle ;  and  at  its  edges  the  choroid 
plexuses  of  the  lateral  ventricles,  v.  I.  :  t.s.  taenia  semicircularis  ;  cr,  forward  prolongation 
of  the  crusta  passing  laterally  into  the  internal  capsule,  i.  c. ;  s.  t.  r.  subthalamic  prolonga- 
tion of  the  tegmentum,  consisting  of  (1 )  the  dorsal  layer,  (2)  the  zona  incerta,  and  (3)  the 
corpus  subthalamicum  ;  «.  ti.  substantia  nigra  ;  n.  c.  nucleus  caudatus  of  the  corpus  stria- 
tum ;  n.  I.  nucleus  lenticularis  ;  <?.  c.  external  capsule  ;  cl.  claustrum  ;  /,  island  of  Keil; 
h,  hippocampus  ;  d,  fascia  dentata. 


Fig.  245. — Horizontal 
section  through  the 
middle  of  the  right 
cerebral  hemisphere. 
(Natural  size.) 

v. I.  lateral  ventricle,  anterior 
cornu  ;  c.  c.  corpus  callo- 
sum :  s.  1.  septum  lucidum  ; 
a./,  anterior  pillars  of  the 
fornix ;  v.  3,  third  ven- 
tricle ;  th,  thalamus  opti- 
cus;  s.t.  stria  terminalis; 
n.  c.  nucleus  caudatus,  and 
7i.  I.  nucleus  lenticularis  of 
the  corpus  striatum  :  i.  c. 
internal  capsule :  g,  its 
angle  or  genu ;  ».  c.  tail  of 
the  nnc  ens  caudatus  ap- 
pearing in  the  descending 
cornu  of  the  lateral  ven- 
tricle ;  cl,  claustrum ;  /, 
island  of  Reil. 


THE   PINEAL   AND   PITUITARY   BODIES 


209 


The  optic  thalamus,  which  lies  at  the  side  of  the  third  ventricle 
and  forms  part  of  the  floor  of  the  lateral  ventricle,  is  covered  externally 
by  a  layer  of  white  fibres,  most  marked  next  to  the  internal  capsule, 
fibres  from  which  pass  into  the  thalamus  and  serve  to  connect  it  with 
the  hemisphere. 

The  grey  matter  of  the  thalamus  (fig.  244)  is  partially  subdivided 
by  an  oblique  white  lamina  into  a  smaller,  inner  (i),  and  a  larger, 
outer,  nucleus  (e) ;  these  contain  a  number  of  small  scattered  nerve- 
cells.  Anteriorly  another  portion  of  grey  matter  (a)  is  divided  off  in  a 
similar  way  ;  this  contains  comparatively  large  nerve-cells. 

Attached  to  the  optic  thalamus  below  and  externally  are  the  two 
geniculate  bodies  which  are  connected  with  the  optic  tract.  The  outer 
geniculate  body  has  a  lamellated  structure  consisting  of  alternating 
layers  of  grey  and  white  matter. 

The  tegmentum  of  the  crus  cerebri  is  prolonged  below  the  thala- 
mus opticus  into  a  mass  of  grey  substance,  with  longitudinally  and 
obliquely  crossing  white  bundles,  which  is  known  under  the  name  of 
subthalamic  region.  In  it  at  least  three  parts  differing  from  one 
another  in  structure  may  be  distinguished  (see  fig.  244,  1,  2,  3). 

The  pineal  gland,  which  is  developed  in  the  roof  of  the  third 
ventricle,  is  composed  of  a  number  of  tubes  and  saccules  lined  and 
sometimes  almost  filled  with  epithelium,  and  containing  deposits  of 
earthy  salts  {brain  sand).     These  may,  however,  occur  in  other  part3 


Fig.  246. — Section  of  the  upper  part  of  the  brain  and  meninges  to  show  the 
RELATIONS   OF   THE   AKAc  HMHIiAL  villi.     (iMagnitied.) 

c.c.  corpus   callosum  ;  /,  falx   cerebri  ;  s.a.  subarachnoid  space,  pervaded  by  a  network   of 
fine  1 1  :  from  it  the  fungiform  villi  are  seen   projecting  into  the  dura  mater. 

Some  are  projecting  into  the  superior  longitudinal  siuu-.  -. 

of  the  brain  as  well.     Tbe  follicles  are  separated  from  one  another  by 
vascular  connective  tissue  derived  from  the  pia  mater. 

The  pituitary  body  is  a  small  reddish  mass  which  lies  in  the  sella 


210  THE   ESSENTIALS   OF  HISTOLOGY 

turcica,  and  is  connected  with  the  third  ventricle  by  the  infundibulum. 
It  consists  of  two  lobes,  a  larger  anterior,  and  a  smaller  posterior. 
The  anterior  lobe  is  originally  developed  as  a  hollow  protrusion  of  the 
buccal  epithelium.  It  consists  of  a  number  of  tubules,  which  are  lined 
by  epithelium,  and  united  by  connective  tissue.  In  some  of  the  tubes 
the  epithelium  is  ciliated,  and  sometimes  a  colloid  substance  like  that 
occurring  in  the  vesicles  of  the  thyroid  has  been  found  in  them. 

The  posterior  lobe  of  the  pituitary  body,  although  developed  from 
the  floor  of  the  third  ventricle,  contains  scarcely  any  perceptible 
nervous  elements  in  the  adult.  It  consists  chiefly  of  vascular  con- 
nective tissue. 

The  membranes  of  the  brain  are  similar  in  general  structure  to  those 
of  the  spinal  cord,  p.  185.  The  dura  mater  is,  however,  more  closely 
adherent  to  the  under  surface  of  the  bony  cavity  than  is  the  case  in 
the  vertebral  canal.  The  arachnoid  is  in  many  places  close  to  the 
dura  mater,  and  separated  by  a  wide  subarachnoid  space,  which  is 
bridged  across  by  finely  reticulating  bands  of  areolar  tissue  (subarach- 
noid trabecular,  fig.  2-46,  s.a.)  from  the  pia  mater.  In  the  vicinity  of 
the  longitudinal  sinus,  small  rounded  elevations  (arachnoidal  villi, 
Pacchionian  glands)  project  into  the  dura  mater,  and  even  become  em- 
bedded in  the  skull  itself. 


211 


LESSON   XXXIX.  and   XL. 

STRUCTURE  OF  THE  EYELIDS  AND  OF  THE  PARTS  OF 
THE  EYEBALL. 


LESSON   XXXIX. 

1.  Section's  of  the  eyelid  vertical  to  its  surfaces  and  transverse  to  its  long 
axis.  The  lid  should  be  hardened  in  alcohol,  and  the  sections  may  be  stained 
with  hematoxylin  and  moiuited  in  the  usual  mannei. 

Notice  the  long  sacculated  Meibomian  glands  lying  in  dense  connective 
tissue  close  to  the  conjunctival  surface,  and  their  ducts  opening  at  the 
margin  of  the  lid.  External  to  these  the  small  fibres  of  the  orbicularis  pal- 
pebrarum cut  across ;  a  few  of  the  fibres  of  the  muscle  lie  on  the  conjunctival 
side  of  the  duct.  A  short  distance  from  the  Meibomian  gland  may  be 
observed  another  tolerably  large  sebaceous  gland  ;  outside  this  again  are  the 
eyelashes.  In  the  skin  covering  the  outer  surface  of  the  eyelid  a  few  small 
hairs  may  be  seen.  At  the  attached  part  of  the  eyelid  are'  some  bundles  of 
involuntary  muscular  fibres  cut  longitudinally  in  the  section,  and  in  the  upper 
eyelid  the  fibrous  attachment  of  the  elevator  muscle  may  be  observed  attached 
to  the  dense  connective  tissue. 

Make  a  general  sketch  under  a  low  power. 

2.  Sections  through  the  posterior  part  of  an  eyeball  that  has  been  hardened 
in  Muller's  fluid.  The  sections  are  stained  and  mounted  in  the  usual  way. 
These  sections  will  show  the  relative  thickness  of  the  several  coats  and  the 
layers  of  which  each  coat  is  formed.  Sections  which  pass  through  the  point 
of  entrance  of  the  optic  nerve  will  also  exhibit  the  manner  in  which  the 
nerve-fibres  pierce  the  several  coats  to  reach  the  inner  surface  of  the  retina. 
The  modifications  which  are  found  in  the  neighbourhood  of  the  yellow  spot 
may  also  be  made  out  if  the  sections  have  been  taken  from  the  human  eye. 

3.  Sections  of  the  anterior  half  of  an  eyeball  which  has  been  hardened  in 
Muller's  fluid.  These  sections  should  pass  through  the  middle  of  the  cornea 
The  lens  may  be  left  in  situ,  but  this  renders  the  preparation  of  the  sections 
and  the  mounting  of  them  much  more  difficult. 

In  these  sections  make  a  general  sketch  under  a  low  power,  showing  the 
relations  of  the  several  parts  one  with  another  ;  and  study  carefully,  and  sketch 
in  detail,  the  layers  of  the  cornea,  the  place  of  junction  of  the  cornea  and 
sclerotic,  the  ciliary  muscle,  the  muscular  tissue  of  the  iris,  the  mode  of  sus- 
pension of  the  lens,  and  the  pars  ciliaris  retinae. 

4.  Mount  in  glycerine  thin  tangential  sections  of  a  cornea  stained  with 
chloride  of  gold  by  Cohnheim's  method.  Sketch  three  or  four  of  the  con- 
nective-tissue cells  (corneal  corpuscles).  The  arrangement  and  distribution 
of  the  nerve-fibres  and  their  termination  amongst  the  epithelium-cells  as 
shown  in  chloride  of  gold  preparations  have  been  alreadv  studied  (Lesson 
XIX.) 

P2 


212  THE    ESSENTIALS   OF   HISTOLOGY 

5.  Mount  in  Canada  balsam  sections  of  a  cornea  which  has  been  stained 
with  nitrate  of  silver.  Notice  the  branched  cell-spaces  corresponding  with 
the  connective-tissue  cells  of  the  last  preparation. 

Tins  preparation  is  best  made  by  rubbing  the  surface  of  the  cornea  with 
lunar  caustic  after  scraping  off  the  epithelium.  After  ten  or  fifteen  minutes 
(by  which  time  the  nitrate  of  silver  will  have  penetrated  the  thickness  of  the 
cornea)  the  eye  is  washed  with  distilled  water,  placed  in  spirit,  and  exposed 
to  the  light.  "When  brown  and  sufficiently  hardened,  tangential  sections  may 
be  made  with  a  razor.] 

LESSON   XL. 

1.  Remove  the  sclerotic  from  the  anterior  part  of  an  e3Te  which  has  been 
preserved  in  Miiller's  fluid,  and  tear  off  thin  shreds  from  the  surface  of  the 
choroid,  including  amongst  them  portions  of  the  ciliary  muscle.  Stain  the 
shreds  with  logwood  and  mount  them  in  Farrant's  solution.  Sketch  the 
branched  pigment-cells,  the  elastic  network,  the  mode  of  attachment  of  the 
fibres  of  the  ciliary  muscle,  &c. 

2.  Injected  preparation  of  choroid  and  iris.  Mount  in  Canada  balsam  por- 
tions of  the  choroid,  coat  and  his  from  an  eye,  the  blood-vessels  of  which  have 
been  filled  with  coloured  injection.  Make  sketches  showing  the  arrangement 
of  the  capillaries  and  veins. 

3.  Teased  preparation  of  retina.  Break  up  with  needles  in  a  drop  of 
glycerine  a  minute  fragment  of  retina  which  has  been  placed  in  1  per  cent, 
osmic  acid  solution  for  a  few  hours,  and  has  subsequently  been  kept  in  dilute 
glycerine.  Complete  the  separation  of  the  retinal  elements  by  tapping  the 
cover-glass.  Draw  carefully  under  a  high  power  some  of  the  isolated 
elements — e.g.  the  rods  and  cones  with  their  attached  fibres  and  nuclei,  the 
inner  granules,  the  ganglion-cells,  the  fibres  of  Midler,  hexagonal  pigment- 
cells.  &c.  In  some  of  the  fragments  the  arrangement  of  the  elements  in  the 
retinal  layers  may  be  made  out  even  better  than  in  actual  sections. 

Measure  the  length  and  diameter  of  some  of  the  cones,  the  length  of  the 
cone-fibres,  and  the  diameter  of  some  of  the  outer  and  inner  nuclei. 

4.  Teased  preparation  of  lens.  Separate  in  water  the  fibres  of  a  crystalline 
lens  which  has  been  macerated  for  some  days  in  wreak  bichromate  of  potash 
solution.     Sketch  some  of  the  fibres,  together  and  separate. 


The  eyelids  (fig.  247)  are  covered  externally  by  the  skin,  and  in- 
ternally or  posteriorly  by  a  mucous  membrane,  the  conjunctiva,  which 
is  reflected  from  them  over  the  globe  of  the  eye.  They  are  composed 
in  the  main  of  connective  tissue,  which  is  dense  and  fibrous  under  the 
conjunctiva,  where  it  forms  what  is  known  as  the  tarsus. 

Embedded  in  the  tarsus  is  a  row  of  long  sebaceous  glands  (the  Mei- 
bomian glands,/),  the  ducts  of  which  open  at  the  edge  of  the  eyelid. 
The  rest  of  the  thickness  of  the  eyelid  is  composed  of  a  somewhat 
loose  connective  tissue,  and  contains  the  bundles  of  the  orbicularis 
muscle  (b).  In  the  upper  eyelid  the  levator  paljoebrcB  is  inserted  into 
the  tarsus  by  a  fibrous  expansion,  and  some  bundles  of  involuntary 
muscle  are  also  present  near  the  attachment  of  the  eyelid.     The  skin 


STRUCTURE   OF   THE   EYELIDS 


213 


has  the  usual  structure  ;  it  contains  small  sweat-glands  and  the  fol- 
licles of  small  hairs,  and,  in  addition,  at  the  edge  of  the  eyelid,  the 
large  hair-follicles  from  which  the  eyelashes  grow.  The  epithelium  of 
the* conjunctiva  palpebral  is  columnar,  passing  at  the  edge  of  the  lid 
into  the  stratified  epithelium  of  the  skin  ;  it  also  becomes  stratified  m 


Fig.  247. 


-Vertical  se<  rios  through  the  upper  eyelid. 
(Magnifii 


a,  skin;  6,  orbicularis  ;  6',  ciliary  bundle  ;  c.  involuntary  muscle  of  eyelid:  d,  conjunct  ja 
Ttersus;  f,  Meibomian  gland;  *  and  near  eyelashes,  with  modified  sweat- 

gland  opening  witb  it;   A,  eyelashes;  i,   small  hairs  in  outer  skin;  j,  sweat-glands. 
t,  posterior  tarsal  glands. 

the  part  which  is  reflected  over  the  globe  of  the  eye.  The  nerves  of 
the  conjunctiva  terminate  for  the  most  part  in  end-bulbs,  which  in 
man  are  spheroidal,  and  formed  chiefly  of  a  small  mass  of  polyhedral 
cells,  but  in  the  calf  and  most  animals  they  are  elliptical,  and  consist 
of  a  core  and  lamellated  sheath  (see  Lesson  XIX.) 


214 


THE   ESSENTIALS   OF   HISTOLOGY 


The  lachrymal  gland  may  be  briefly  mentioned  in  connection  with 
the  eyelid.  It  is  a  compound  racemose  gland,  yielding  a  watery  secre- 
tion, and  resembling  in  structure  the  serous  salivary  glands,  such  as 
the  parotid. 


m\— 


Fig.  248.— Vertical  section  of  human  cornea  from  near  the  margin. 

(Magnified.) 

1,  epithelium;  2,  anterior  homogeneous  lamina;  3.  substantia  propria  corneas;  4,  posterior 
homogeneous  ("elastic)  lamina;  S,  epithelium  of  the  anterior  chamber;  a,  oblique  fibres 
in  the  anterior  layer  of  the  substantia  propria;  6,  lamellae,  the  fibres  of  which  are  cut 
across,  producing  a  dotted  appearance  ;  c,  corneal  corpuscles  appearing  fusiform  in  section; 
d,  bundles  of  fibres  cut  longitudinally  ;  e,  transition  to  the  sclerotic,  with  more  distinct 
fibrillation,  and  surmounted  by  a  thicker  epithelium  ;  /,  small  blood-vessels  cut  across 
near  the  margin  of  the  cornea. 


The  sclerotic  coat  is  composed  of  dense  fibrous  tissue,  the  bundles 
of  which  are  intimately  interlaced.     It  is  thickest  at  the  back  of  the 


STRUCTURE   OF  THE   COATS   OF  THE   EYEBALL  215 

eyeball.  It  is  covered  externally  with  a  lymphatic  epithelium,  while 
internally  it  is  lined  by  a  layer  of  connective  tissue  containing  pig- 
ment-cells, which  give  it  a  brown  appearance  (lamina  fusca).  At  the 
entrance  of  the  optic  nerve  the  sclerotic  is  prolonged  into  the  sheath 
of  that  nerve,  the  bundles  of  which,  piercing  the  coat,  give  a  sieve-like 
aspect  to  the  part  (lamina  cribrosa,  fig.  257,  L). 

The  cornea  ifig.  248)  consists  of  the  following  layers  enumerated 
from  before  back  : 

1.  A  stratified  epithelium  continuous  with  the  epithelium  of  the 
conjunctiva  (1 ). 

2.  A  thin  lamina  of  homogeneous  connective  tissue  (membrane  of 
Bowman),  upon  which  the  deepest  cells  of  the  epithelium  rest  (2). 

3.  A  thick  layer  of  fibrous  connective  tissue  which  forms  the 
proper  substance  of  the  cornea  (3).  This  is  continuous  laterally  with  the 
tissue  of  the  sclerotic.  It  is  composed  of  bundles  of  white  fibres 
arranged  in  regular  laminae,  the  direction  of  the  fibres  crossing  one 
another  at  right  angles  in  the  alternate  laminae.  Between  the  laminae 
lie  flattened  connective-tissue  corpuscles,  which  are  branched  and 
united  by  their  processes  into  a  continuous  network  ;  there  is  of  course 
a  corresponding  network  of  cell-spaces  (fig.  249,  A,  B).      In  vertical 


Fig.  249.— a.  Corpus*  les  of  the  rat'-  cornea.  (From  a  preparation  treated 
with  chloride  of  gold.)  b.  Cell-spai  es  of  the  rat's  cornea.  (From  a 
preparation  stained  with  nitrate  of  silver.) 

sections  the  cells  appear  narrow  and  spindle-shaped  (fig.  248,  c).  In 
the  superficial  lamina;  there  are  a  few  bundles  of  fibres  which  run 
obliquely  towards  the  surface 

4.  A  homogeneous  elastic  layer  1  membrane  of  Desccmet  1 1  fig.  248,  0. 
This  completely  covers  the  back  of  the  cornea,  but  at  the  angle  which 
the  cornea  forms  with  the  iris  it  breaks  up  into  separate  fibres,  which 
are  continued  into  the  iris  as  the  ligamentum  pectination,  or  pill; 
the  iris. 


216 


THE   ESSENTIALS   OF  HISTOLOGY 


5.  A  layer  of  pavement-epithelium  covering  the  posterior  surface  of 
the  elastic  lamina,  and  lining  the  front  of  the  anterior  chamber  of  the 
eye  (fig.  348,  5).  At  the  sides  it  is  continued  over  the  ligamentum 
pectinatiun  into  a  similar  epithelium,  covering  the  anterior  surface 
of  the  iris  (fig.  253,  J\T). 

The  nerves  of  the  cornea  pass  in  from  the  periphery,  losing  their 
medullary  sheath  as  they  enter  the  corneal  substance.  They  form 
a  primary  plexus  in  the  substantia  propria,  a  secondary  or  sub-epit- 
helial plexus  immediately  under  the  epithelium  which  covers  the 
anterior  surface,  and  a  terminal  plexus  of  fine  fibrils  which  pass  frorn 
the  sub-epithelial  plexus  in  pencil-like  tufts  and  become  lost  between 
the  epithelium-cells  (see  figs.  105,  106,  Lesson  XIX.)  There  are  no 
blood-vessels  or  lymphatics  in  the  cornea,  although  they  come  close 
up  to  its  margin. 

The  choroid  or  vascular  coat  of  the  eye  is  of  a  black  colour  in  many 
animals,  but  in  the  human  eye  is  dark  brown.  It  is  composed  of  connec- 
tive tissue,  the  cells  of  which  are  large  and  filled  with  pigment  (fig.  251), 
and  it  contains  in  its  inner  part  a  close  network  of  blood-vessels,  and 


6M0»KE."Si7»tr 


Fig.  250. — Section  of  choroid.     (Cacliat.) 


«,  membrane  of  Bruch  :  the  chorio-capillaris  is  just  above  it;   6.  vascular  layer;  e,  vessels 
with  blood-corpuscles  ;  d,  lamina  suprachoroid^. 


in  its  anterior  part  the  involuntary  muscular  fibres  of  the  ciliary 
muscle,  which  pass  backwards  from  their  origin  at  the  junction  of  the 
cornea  and  sclerotic,  to  be  inserted  into  the  choroid.  The  choroid  is 
separable  into  the  following  layers,  enumerated  from  without  in 
(fig.  250)  : 

1.  The  lamina  suprachoroidea  (fig.  250,  d).  This  is  a  thin  mem- 
brane composed  of  homogeneous  connective  tissue  pervaded  by  a  net- 
work of  fine  elastic  fibres,  and  containing  many  large  branched 
pigment-cells  and  lymph-corpuscles  (fig.  251).  It  is  covered  super- 
ficially by  a  delicate  lymphatic  epithelium,  and  is  separated  from  the 
lamina  fusca  by  a  cleft -like  lymphatic  space  which  is  bridged  across 
here  and  there  by  the  passage  of  vessels  and  nerves,  and  by  bands  of 
connective  tissue. 

2.  The  vascular  layer  of  the  choroid  (fig.  250,  b),  which  resembles 


STRUCTURE   OF   THE    CHOROID   COAT 


217 


Fig.  251.— A  small  portion  of  the  lamina  suprachoroidea.    (Highly  magnified.) 

p,  pigment-cells;/,  elastic  fibre* ;  n.  nuclei  of  epitbelioid  cells  (the  outlines  of  the 
cells  are  not  indicated) ;  /,  lymph-cells. 


Fig.  252.— Injected  beood-vessels  of  the  choroid  coat, 

1,  one  of  the  larger  vein- :  2.  <mall  anastomosing  vessels;  3,  branches 
dividing  into  the  smallest  vessels. 


118 


THE    ESSENTIALS   OF   HISTOLOGY 


the  suprachoroidea  in  structure,  but  contains  the  blood-vessels  of  the 
coat.  In  its  outer  part  are  the  larger  vessels  (arteries  and  veins),  the 
veins  having  a  peculiar  vorticose  arrangement ;  in  its  inner  part 
lehouo-capillaris)  are  the  capillaries,  which  form  an  extremely  close 
network   with  elongated  meshes,    the  capillaries  radiating  from  the 


Fig.  253. — Section    (from    the    eye   of   a   max,  aged   SO),  showing   the 

RELATIONS   OF     THE    CORNEA,    SCLEROTIC,    AND     IRIS,    TOGETHER    WITH     THE 
CILIARY    MUSCLE,    AND    HIE    CAVERNOUS     SPACES    NEAR    THE    ANGLE    OF   THE 

anterior  chamber.     (Magnified.) 

a,  epithelium  ;  b,  conjunctival  mucous  membrane  ;  c,  sclerotic  ;  d.  membrana  suprachoroidea; 
E,  opposite  the  ciliary  muscle  :  P,  choroid,  with  ciliary  processes  ;  G,  tapetum  nigrum  and 
pars  ciliaris  retinas ;  ir,  cornea  (substantia  propria) ;  j,  iris;  K,  radiating  and  meridional, 
and  l,_  circular  or  annular  bundles  of  the  ciliary  muscle  ;  m.  bundles  passing  to  the 
sclerotic;  x,  ligamentum  pectinatum  iridis  at  the  angle,  o,  of  the  anterior  chamber; 
P,  line  of  attachment  of  the  iris.  1,  anterior  hi  I  aminaof  the  cornea  :  2.  posterior 

homogeneous  lamina,  covered  with  epithelial  cells  which  are  continued  over  the  front  of 
the  iris  ;  3,  cavernous  spaces  at  the  angle  of  the  anterior  chamber  (spaces  of  Fontana »  ; 
4,  canal  of  Schlemm,  with  epithelial  lining,  and  with  a  vessel,  5,  leading  from  it;  6,  other 
vessels  ;  7,  bundles  of  fibres  of  the  sclerotic  having  a  circular  direction,  cut  ai 
8,  larger  ones  in  the  substance  of  the  sclerotic ;  9,  fine  bundles  cut  across,  at  limit  of 
cornea:  10,  point  of  origin  of  meridional  bundles  of  ciliary  muscle;  11,  blood-vessels  in 
sclerotic  and  conjunctiva,  cut  across  ;  12,  section  of  one  of  the  ciliary  arteries. 

extremities  of  the  small  arteries  and  veins  in  a  highly  characteristic 
manner  (fig.  252).  In  the  ciliary  processes  the  vessels  have  for  the 
most  part  a  longitudinal  direction,  but  there  are  numerous  convoluted 
transversely  disposed  capillaries  uniting  the  longitudinal  vessels  (fig.  255). 


STRUCTURE   OF  THE   IRIS 


219 


3.  Lining  the  inner  surface  of  the  choroid  is  a  very  thin  trans- 
parent membrane  known  as  the  membrane  of  Bruch  (fig.  250,  a). 

The  ciliary  muscle  of  Bowman  consists  of  involuntary  muscular 
bundles  which  arise  at  the  corneo-sclerotic  junction,  and  pass  meri- 
dionally  backwards  to  be  inserted  into  the  choroid  (fig.  253,  K).  Many 
of  the  deeper- seated  bundles  take  an  oblique  direction,  and  these  pass 
gradually  into  others  which  run  circularly  around  the  circumference 
of  the  iris,  and  on  a  level  with  the  ciliary  processes.  This  set  of 
circularly  arranged  bundles  constitutes  the  circular  ciliary  muscle  of 
H.  Mutter  (l);  it  is  most  marked  in  hypermetropic  eyes. 

The  iris  is  that  part  of  the  vascular  coat  of  the  eye  which  extends 
in  front  of  the  lens.     It  is  continuous  with  the  choroid   and  has  a 


Fig,  254. — Segment  <>f  the  iris,  >een-  prom  the  pos- 
terior SCRFAl  K  AFTER  REMOVAL  OF  THE  UVEAL 
PIGMENT. 

«,  sphincter  muscle  ;  b,  dilatator  muscle  of  the  pupil. 


Fig.  255. — Vessels  of  the  choroid,  ciliary  pro<  i  3SES3 
AND  IRIS  OF  A  CHILD.     (  10  diameters.) 

a,  capillary  network  of  the  posterior  part  of  the  choroid,  ending 
at  h,  theora  serrata;  e,  arteries  of  the  corona  ciliaris,  supplying 
the  ciliary  |  and  passing  into  the  iris,e;/,  the  ca- 

pillary network  close  to  the  pupillary  margin  of  the  iris. 


similar  structure,  but  its  pigment-cells  often  contain  coloured  pigment. 
Besides  the  homogeneous  connective  tissue,  with  numerous  elastic  fibres 
and  blood-vessels  of  which  it  is  chiefly  composed,  it  contains  two  sets 
of  plain  muscular  fibres.  The  one  set  forms  the  sphincter  muscle  (fig. 
245,  a  \,  which  encircles  the  pupil,  the  other  set  consists  of  a  flattened 
layer  of  radiating  fibres  which  extend  from  the  attachment  of  the  iris 
Dearly  to  the  pupil,  lying  close  to  the  posterior  surface  and  constituting 
the  dilatator  muscle  (b). 

The  back  of  the  iris  is  covered  by  a  thick  layer  of  pigmented 
epithelium  i  uvea  i  continuous  with  the  epithelium  of  the  pars  ciliaris 
retinae. 

The  blood-vessels  of  the  iris  converge  towards  the  pupil  (fig.  255,  C). 


220 


THE   ESSENTIALS   OF   HISTOLOGY 


Near  the  pupil  the  small  arteries  form  a  small  anastomotic  circle,  from 
which  capillaries  arise  and  pass  still  nearer  the  pupil,  around  which 
they  form  a  close  capillary  network. 

A  large  number  of  nerve-fibres  are  distributed  to  the  choroid  and 
iris,  probably  going  chiefly  to  the  muscular  tissue  (ciliary  muscle  and 
sphincter  and  dilatator  iridis). 

The  retina  consists  of  the  eight  layers  shown  in  the  accompanying 
figure  (fig.  256),  numbered  as  they  occur  from  within  out. 


Outer  or  choroidal  surface. 


8.  Layer  of  pigment-cells. 


Laver  of  rods  and  cones. 


Membrana  limitans  externa. 


6.  Outer  nuclear  laver. 


5.  Outer  molecular  layer. 


4.  Inner  nuclear  layer. 


\W- 


3.  Inner  molecular  layer. 


2.  Layer  of  nerve-cells. 

1.  Layer  of  nerve-fibres. 

.    .  Membrane  limitans  interna. 
Inner  surface. 

Fig.  2.J6. — Diagrammatic  section  <>f  the  human  retina. 


The  inner  surface  of  the  retina,  which  is  smooth,  rests  upon  the 
hyloid  membrane  of  the  vitreous  humour.  It  is  formed  of  the  united 
bases  of  the  fibres  of  Miiller,  which  will  be  afterwards  described. 

The    layer   of  nerve-fibres   is    formed    by    the    expansion   of   the 


STRUCTURE   OF   THE   RETINA 


221 


optic  nerve  after  it  has  passed  through  the  coats  of  the  eye  (fig.  257). 
At  its  entrance  it  forms  a  slight  eminence  (colliculus  nervi  opiici). 
The  nerve-fibres  lose  their  medullary  sheath  on  reaching  the  retina. 
The  layer  becomes  gradually  thinner  in  the  anterior  part  of  the  retina. 


<£fr&™^z* 


Ve     'YmAr 


Fig.  257. — Section  through  the  coats  of  the  eyeball  at  the  point  of 

ENTRANCE    OF   THE   OPTIC    NERVE.      (Toldt.) 

Ve.  dural  sheath  ;  Vm,  arachnoidal  sheath,  and  17.  pia-matr.il  sheath  of  the  optic  nerve,  with 
lymphatic  spaces  between  them  :  0,  ".  funiculi  of  the  nerve  :  L,  lamina  cribrosa  ;  A,  central 
artery  :  S,  sclerotic  :  Ch,  choroid  :  R,  retina.  The  small  letters  refer  to  the  various  parts  of 
the  retina,  b  being  the  layer  of  rods  and  cones,  and  t  that  of  nerve-fibres. 


The  layer  of  nerve-cells,  or  ganglionic  layer,  is  composed  of  large 
nerve -cells  somewhat  like  the  cells  of  Purkinje  of  the  cerebellum,  and 
having  on  the  one  side  a  fine  axis-cylinder  process  prolonged  into  a 
nerve-fibre,  and  on  the  other  a  thick  branching  process,  the  ramifica- 
tions of  which  become  lost  in  the  next  layer. 

The  inner  molecular  layer  is  comparatively  thick,  and  has  an 
appearance  very  like  the  neuroglia  of  the  grey  matter  of  the  nerve- 
centres.  A  few  nuclei  are  scattered  through  it,  and  it  is  traversed  by 
the  processes  of  the  nerve-cells  and  of  the  inner  granules,  as  well  as  by 
the  fibres  of  Muller. 

The  inner  nuclear  layer  is  mainly  composed  of  bipolar  cells  con- 
taining large  nuclei  {inner  granules).  The  processes  of  these  cells 
extend  on  the  one  hand  inwards  through  the  inner  molecular  layer, 
probably  to  join  with  nerve-fibres  or  with  the  processes  of  the  gan- 
glion-cells, whilst  the  other  process  is  directed  outwards,  and  is  con- 
nected with  the  extremity  of  a  rod  or  cone  fibre.  Besides  these  bipolar 
cells,  there  are  other  inner  granules  which  are  different  in  character, 
being  devoid  of  processes  and  resting  on,  or  even  embedded  in,  the 


222  THE  ESSENTIALS  OF  HISTOLOGY 

inner  molecular  layer,  with  the  formation  of  which  they  are  probably 
connected.  Others,  which  are  larger  and  more  rounded,  are  applied 
to  the  outer  molecular  layer.  The  fibres  of  Midler  have  nucleated 
enlargements  hi  the  inner  nuclear  layer. 

The  outer  molecular  layer  is  thin,  and  is  composed  of  flattened  and 
branched  cells,  the  ramified  cell-processes  being  united  into  a  close 
network  (fig.  258). 


Fig.  258. — Branched  cells  with  the  uniting  feltwork  of  fibres  from  the 
outer  molecular  layer  of  the  horse's  retina. 

As  far  as  the  outer  molecular  layer  the  retina  may  be  said  to  con- 
sist of  nervous  elements,  but  beyond  this  layer  it  is  formed  of  modified 
epithelium-cells. 

The  outer  nuclear  layer  and  the  layer  of  rods  and  cones  are  com- 
posed of  elements  which  are  continuous  through  the  two  layers,  and 
they  should  properly,  therefore,  be  described  as  one.  It  may  be  termed 
the  neural  or  sensory  epithelium  of  the  retina  (fig.  260,  G  and  7).  The 
elements  of  which  the  neural  epithelium  consists  are  elongated,  nucle- 
ated cells  of  two  kinds.  The  most  numerous,  which  we  may  term  the 
rod-elements,  consist  of  peculiar  rod-like  structures  (rods  proper)  set 
closely  side  by  side,  and  each  of  which  is  prolonged  internally  into  a  fine 
varicose  fibre  (rod-fibre)  which  swells  out  at  one  part  of  its  course  into 
a  nucleated  enlargement.  The  rod  proper  consists  of  two  segments,  an 
outer  cylindrical  and  transversely  striated  segment,  which  during  life 
has  a  purplish-red  colour,  and  an  inner  slightly  bulged  segment,  which 
in  part  of  its  length  is  longitudinally  striated.  The  nucleus  of  the 
rod-element  often  has,  in  the  fresh  condition,  a  transversely  shaded 
aspect  (fig.  259).  The  cone-elements  are  formed  of  a  conical  taper- 
ing external  part,  the  cone  proper,  which  is  directly  prolonged  into 
a  nucleated  enlargement,  from  the  farther  side  of  which  the  cone- 
fibre,  considerably  thicker  than  the  rod-fibres,  passes  inwards,  to  ter- 
minate by  an  expanded  base  at  the  outer  molecular  layer.  The  cone 
proper,  like  the  rod,  is  formed  of  two  segments,  the  outer  of  which, 
much  the  smaller,  is  transversely  striated,  the  inner,  bulged  segment 


STRUCTURE   OF   THE   RETINA 


223 


Fig.  259. — Diagrammatic  representation  of  the  nervous  and  epithelial 

ELEMENTS   OF   THE    RETINA. 

1  to  5,  nervous  elements.    6,  7,  epithelial  elements.    The  designation  of  the  numbers  is  the  same  as 
in  fig.  346.    The  extent  of  the  molecular  layers  is  indicated  merely  by  linear  shading. 


224 


THE   ESSENTIALS   OF   HISTOLOGY 


being  longitudinally  striated.  The  inner  ends  of  the  rod-  and  cone- 
fibres  are  believed  to  be  connected  with  processes  from  the  inner 
granules,  and  through  these  with  the  nerve-cells  and  nerve-fibres.  In 
birds,  reptiles,  and  amphibia,  a  small  oil-globule,  often  brightly 
coloured  red,  yellow,  or  green,  is  found  in  the  inner  segment  of  each 
cone,  and  other  variations  of  structure  are  met  with  in  animals.  The 
cones  are  most  numerous  at  the  back  of  the  retina  ;  they  are  fewer  in 
number,  and  the  rods  are  proportionally  more  numerous,  towards  the 
anterior  part. 


tM.  I. 


Fig.  260. — Pigmented  epithelium  of  the 
human  retina.  (Highly  magnified.) 

a,  cells  seen  from  the  outer  surface  with  clear 
lines  of.  intercellular  substance  between  ;  b,  two 
cells  seen  in  profile  with  fine  offsets  extending 
inwards  ;  c,  a  cell  still  in  connection  with  the 
outer  ends  of  the  rods. 


Fig.  261. — A  fibre  of  Muller  from  the 

HUMAN    RETINA,  ISOLATED.      w?° 

6,  base  of  the  fibre ;  n,  its  nucleus ;  m.e.l.  mem- 
brana  limitans  externa;  e.m.l.  external  mo- 
lecular layer. 


The  ■pigmentary  layer  is  the  most  external  part  of  the  retina.  It  is 
formed  of  hexagonal  epithelium-cells  (fig.  260),  which  are  smooth  exter- 
nally where  they  rest  against  the  choroid,  but  are  prolonged  internally 
into  fine  filaments  which  extend  between  the  rods.  The  pigment-granules, 


STRUCTURE   OF  THE   RETINA 


225 


many  of  which  are  in  the  form  of  minute  crystals,  He  in  the  inner 
part  of  the  cell,  and  after  prolonged  exposure  to  the  light  they  are 
found  extending  along  the  cell-processes  between  the  rods  (b,  c),  their 
function  being  probably  connected  with  the  restoration  of  the  purple 
colouring  matter  which  has  been  bleached  by  the  light. 

Fibres  of  Midler. — The  fibres  of  Miiller  (fig.  261 )  are  long  stiff  fibres 
which  pass  through  several  of  the  retinal  layers.  Commencing  at  the 
inner  surface  of  the  retina  by  expanded  bases  which  unite  with  one 
another  to  form  the  so-called,  internal  limiting  membrane  (fig.  356),  the 
fibres  pass  through  all  the  layers  in  succession,  until  they  reach  the 
outer  nuclear  layer.  Here  they  branch  and  expand  into  a  sort  of  reti- 
cular tissue  which  serves  to  support  the  fibres  and  nuclei  of  the  rod-  and 
cone-elements.  At  the  bases  of  the  rods  and  cones,  this  sustentacular 
tissue  ceases,  being  here  bounded  by  a  distinct  margin  which  has  been 
called  the  external  limiting  membrane  [m.  e.  I.),  but  delicate  sheaths 
have  been  described  passing  from  it  round  the  bases  of  the  rods  and 
cones.  Each  Miillerian  fibre,  as  it  passes  through  the  inner  nuclear 
layer,  has  a  nucleated  enlargement  (n),  indicating  the  original  cell 
nature  of  the  fibre. 

There  are  two  parts  of  the  retina  which  call  for  special  description. 

The  macula  lutea  (yellow  spot,  fig.  268),  with  its  central  fovea,  lies 
in  the  visual  axis,  and  is  the  part  of  the  retina  which  is  most  immedi- 


Fig.  262.— Vertical  section  through  the  macula  lutea  and  fovea  centralis  ; 

diagrammatic. 

1,  nerve-layer ;  2,  ganglionic  layer  ;  3.  inner  molecular :  4,  inner  nuclear  ;  and  5,  outer  molecu- 
lar layers :  6,  outer  nuclear  laj  er,  the  inner  part  with  only  cone-flbres  forming  the  so-called 
external  fibrous  layer  ;  7,  cones  and  rods. 


ately  concerned  in  direct  vision.  It  is  characterised  first  by  its  greater 
thickness  (except  at  the  fovea),  secondly  by  the  large  number  of 
ganglion-cells,  which  are  all  distinctly  bipolar  (2),  and  thirdly  by  the 
large  number  of  cones  it  contains  as  compared  with  the  rods.     In  the 

Q 


226 


THE   ESSENTIALS   OF  HISTOLOGY 


central  fovea  itself  there  are  no  rods,  and  the  cones  are  very  long  and 
slender  ;  moreover,  all  the  other  layers  become  gradually  thinned 
down  almost  to  complete  disappearance,  so  that  the  middle  of  the  central 
fovea  is  the  thinnest  part  of  the  retina.  Since  there  are  few  rods,  the 
outer  nuclear  layer  |  (J  i  loses  in  great  measure  its  appearance  of  being 
composed  of  closely  packed  nuclei,  and  the  cone-fibres  are  very  distinct. 
The  direction  of  all  the  fibres  is  very  oblique  in  this  part  of  the  retina. 
The  pars  ciliaris  retina  which  commences  at  the  ora  serrata,  where 
the  retina  proper  abruptly  ends,  is  composed  of  two  epithelial  layers 
(fig.  263 j,  and  has  no  nervous  structures.      Of  the  two  layers,  the 


Fig.    263. — A    small    portion    of 

THE   CILIARY    PART    OF    THE    RE- 
TINA.    (350  diameters.) 
1,  pigment-cells  ;  2,  columnar  cells. 


external  is  a  thick  stratum  of  pigmented  epithelium  formed  of  rounded 
cells  and  continuous  with  the  pigmentary  layer  of  the  retina  on  the 
one  hand,  and  with  the  uvea  of  the  iris  on  the  other  ;  the  inner  is  a  layer 
of  columnar  cells  each  containing  an  oval  nucleus. 

The  retina  contains  but  few  blood-vessels.  The  artery  enters  and 
the  vein  leaves  it  in  the  middle  of  the  optic  nerve.  The  larger  vessels 
ramify  in  the  nerve-fibre  layer,  and  there  are  capillary  networks  in 
this  layer  and  in  the  inner  nuclear  layer.  There  are  peri-vascular 
lymphatic  spaces  around  the  veins  and  capillaries.  The  neural  epithe- 
lium receives  no  blood-vessels,  but  is  nourished  from  the  vessels  of  the 
choroid. 

Structure  of  the  lens.  The  lens  is  a  laminated  fibrous  body  en- 
closed by  a  transparent  elastic  capsule  into  which,  around  the  circum- 


Fig.  2G4. — Section  through  the  margin  of  the  rabbit's  lens,  showing  the 

TRANSITION    OF   THE    EPITHELIUM    INTO   THE    LENS-FIBRES. 


ference,  the  fibres  of  the  suspensory  ligament  are  inserted.  Immedi- 
ately within  the  capsule,  in  front  and  at  the  sides,  there  is  a  layer  of 
cubical  epithelium  termed  the  epithelium  of  the  capsule,  but  at  the 
margin  of  the  lens  the  cells  become  longer  and  pass  by  a  gradual 
transition  into  the  lens-fibres  (fig.  264).  The  fibres  which  compose  the 
lens  are  long  and  riband-shaped,  with  finely  serrated  edges  (fig.  265,  A) ; 


STRUCTURE   OF  THE   LENS   AND   VITREOUS   HUMOUR     227 

in  transverse  section  they  appear  prismatic  I B  i.  Many  of  the  superficial 
fibres  are  nucleated  (c),  the  lens-fibres  having  originally  been  developed 
by  the  elongation  of  epithelium -cells. 


Fig.  265. — Fibres  of  the  crystalline  lens.    (350  diameters.) 

A,  longitudinal  view  of  the  fibres  of  the  lens  from  the  ox,  showing  the  serrated  edges.  B, 
transverse  section  of  the  fibres  of  the  leus  from  the  human  eye.  C,  longitudinal  view  of 
a  few  of  the  fibres  from  the  equatorial  region  of  the  human*  lens.  Most  of  the  fibres  in 
C  are  seen  edgeways,  and,  towards  1.  present  the  swellings  and  nuclei  of  the  'nuclear 
zone  ; '  at  2,  the  flattened  sides  of  two  fibres  are  seen. 

The  vitreous  humour  is  composed  of  soft  gelatinous  tissue,  appa- 
rently structureless  when  examined  in  the  fresh  condition,  but  contain- 
ing a  few  scattered  amoeboid  cells,  the  processes  of  which  are  often  long 
and  varicose,  and  the  cell-bodies  distended  by  large  vacuoles.  The 
hyaloid  membrane,  which  invests  the  vitreous  humour,  is  homogeneous 
and  structureless  except  in  the  region  of  the  ciliary  processes,  where  it  is 
fibrous  in  structure,  forming  the  zonule  of  Zinn  and  spreading  out  into 
the  suspensory  ligament  of  the  lens. 

02 


228  THE   ESSENTIALS   OF  HISTOLOGY 


LESSON   XLI. 

STRUCTURE   OF  THE   OLFACTORY  MUCOUS  MEMBRANE 
AND   OF  THE  EXTERNAL   AND   MIDDLE    EAR. 

1.  Vertical  sections  of  the  olfactory  mucous  membrane.  The  sections  may 
be  carried  either  across  the  middle  turbinate  bone,  after  decalcification  in 
0"2  per  cent,  chromic  acid,  or  across  the  upper  part  of  the  nasal  septum. 
Make  a  sketch  under  the  low  power.  Notice  the  difference  in  the  character 
of  the  epithelium  in  the  olfactory  and  respiratory  parts  of  the  membrane. 

2.  Teased  preparation  of  the  epithelium  of  the  olfactory  mucous  mem- 
brane. Apiece  of  the  membrane  is  placed  quite  fresh  in  osmic  acid  (1  per 
cent.)  for  a  few  horns,  and  is  then  macerated  for  two  days  or  more  in  water. 
The  epithelium  is  broken  up  in  dilute  glycerine  ;  the  cells  easily  separate 
from  one  another  on  tapping  the  cover-glass.  Notice  the  two  kinds  of  cells. 
Sketch  some  of  the  cells  under  a  high  power. 

3.  Sections  of  the  external  ear  (these  have  been  already  studied  for  the 
cartilage,  Lesson  XII.) 

4.  Sections  across  the  cartilaginous  part  of  the  Eustachian  tube.  Sketch 
under  the  low  power. 

5.  Preparation  of  the  membrana  tympani.  A  piece  of  the  membrane, 
stained  with  hematoxylin,  and  mounted  flat  in  Canada  balsam. 

Determine  the  composition  of  the  membrane — i.e.  the  several  layers  com- 
posing it — by  focussing  carefully  with  the  high  power. 


STRUCTURE  OF  THE   OLFACTORY  MUCOUS   MEMBRANE. 

The  olfactory  region  of  the  nasal  fossae  includes  the  upper  and 
middle  turbinate  processes  and  the  upper  third  of  the  septum.  It  is 
covered  by  a  soft  vascular  mucous  membrane  of  a  yellow  colour  in  man. 

T\\e  epithelium  oi  the  olfactory  mucous  membrane  (figs.  266,  267  lis 
very  thick  and  is  composed  of  long  tapering  cells,  set  closely  side  by 
side  and  bounded  superficially  by  a  cuticular  lamina,  through  which  the 
free  ends  of  the  cells  project.  The  cells  are  of  two  kinds  :  1.  Long 
narrow  spindle-shaped  or  bipolar  cells  consisting  of  a  larger  part  or 
body  (b),  containing  the  nucleus,  and  of  two  processes  or  poles,  one  (c) 
straight  and  cylindrical  and  extending  to  the  free  surface,  the  other  \d) 
very  delicate  and  varicose,  looking  not  unlike  a  nerve-fibril  and  extending 


THE   OLFACTORY   MEMBRANE 


229 


down  to  the  corium.  The  position  of  the  nuclear  enlargement  varies, 
and  with  it  the  relative  length  of  the  two  processes.  The  distal  or  free 
process  terminates  in  a  small  clear  projection,  which  passes  beyond  the 
cuticular  membrane ;  in  amphibia,  reptiles,  and  birds,  and  perhaps  in  some 


Fig.  2G6.— Cells  and  terminal  nerve-firres  of  the  olfactory  region. 
(Highly  magnified.) 

1,  from  the  frog ;  2,  from  man  ;  a,  epithelial  cell,  extending  deeply  into  a  ramified  process : 
i:  olfactory  cells  ;  e.  their  peripheral  rods  ;  e,  their  extremities,  seen  in  I  to  be  prolonged 
into  tine  hair?  ;  </.  their  central  filaments. 

mammals,  it  bears  fine  stiff  hairlike  filaments  (e).  The  proximal  or  vari- 
cose process  becomes  lost  amongst  the  plexus  of  olfactory  nerve-fibrils  at 
the  base  of  the  epithelium,  and  is  believed  to  be  connected  with  a  fibril. 
These  cells  have  accordingly  been  termed  olfactory  cells.  2.  Long  colum- 
nar epithelium  cells  (a),  with  comparatively  broad  cylindrical  nucleated 
cell-bodies  placed  next  the  free  surface,  and  long,  forked,  and  branching 
tail-like  processes  extending  down  to  the  corium.  These  are  usually 
regarded  not  as  sensory  epithelium-cells,  but  merely  as  serving  to  support 
the  proper  olfactory  cells ;  but,  according  to  Exner.  they  are  also  con- 
nected with  the  olfactory  fibres,  and  there  is  no  sharp  distinction 
between  them  and  the  bipolar  cells.  3.  Tapering  cells  are  present,  at 
least  in  some  animals,  in  the  deeper  part  of  the  epithelium.  They  rest 
by  their  bases  upon  the  corium,  and  project  between  the  other  cells, 
which  they  assist  to  support. 

The  corium  of  the  olfactory  mucous  membrane  is  also  very  thick 
(fig.  267).  It  contains  numerous  blood-vessels,  bundles  of  the  olfactory 
nerve-fibres  (which  are  non-medullated),  and  a  large  number  of  serous 


230 


THE   ESSENTIALS   OF  HISTOLOGY 


glands  known  as  Bowman's  glands  (b),  which  open  upon  the  surface 
by  fine  ducts  passing  between  the  epithelium-cells. 


Fig.  267. — Section'  of  olfactory  mucocs  membrane.    (Cadiat.) 
a,  epithelium  ;  b,  glands  of  Bowman;  c,  nerve-bundles. 


STRUCTURE   OF  THE  AUDITORY  ORGAN. 

The  external  ear  proper  [pinna)  is  composed  of  elastic  fibro-carti- 
lage.  invested  by  a  thin,  closely  adherent  skin.  The  skin  is  covered  by 
small  hairs,  and  connected  with  these  are  the  usual  sebaceous  follicles. 
In  some  parts — e.g.  the  lobule — there  is  a  considerable  amount  of 
adipose  tissue  ;  and  voluntary  muscular  fibres  are  hi  places  attached  to 
the  cartilage  and  may  be  seen  in  sections  of  the  ear. 

The  external  auditory  meatus  is  a  canal  formed  partly  of  cartilage 
continuous  with  that  of  the  pinna,  partly  of  bone.  It  is  lined  by  a 
prolongation  of  the  skin  and  is  closed  by  the  membrana  tympani,  over 
which  the  skin  is  prolonged  as  a  very  thin  layer.  Near  the  orifice  the 
skin  has  hairs  and  sebaceous  glands,  and  the  meatus  is  also  provided 
throughout  the  cartilaginous  part  with  small  convoluted  tubular  glands 
of  a  brownish-yellow  colour,  which  yield  a  waxy  secretion  (ceruminous 
glands).     They  appear  to  represent  modified  sweat-glands. 

The  tympanum  is  lined  by  a  mucous  membrane  which  is  continuous 
through  the  Eustachian  tube  with  the  mucous  membrane  of  the 
pharynx  ;  it  is  also  prolonged  into  the  mastoid  cells.  The  epithelium 
is  columnar  and  ciliated  in  some  parts,  but  in  others — e.g.  roof,  promon- 
tory, ossicles,  and  membrana  tympani — it  is  a  pavement-epithelium. 

The  membrana  tympani  is  a  thin  membrane  formed  of  fibrous 
bundles  which  radiate  from  the  umbo.  Within  the  radial  fibres  are  a 
few  annular  bundles.  Covering  the  fibrous  membrane  externally  is  a  thin 


STRUCTURE  OF  THE  EUSTACHIAN  TUBE 


231 


layer  continuous  with  the  skin  of  the  meatus  ;  covering  it  internally  is 
another  thin  layer,  derived  from  the  mucous  membrane  of  the  tympanic 
cavity.  Blood-vessels  and  lymphatics  are  distributed  to  the  membrane 
chiefly  in  the  cutaneous  and  mucous  layers. 

The  Eustachian  tube  is  the  canal  leading  from  the  tympanum  to 
the  pharynx.     It  is  formed  of  bone  near  the  tympanum,  but  below, 


Fig.  268. — Section  across  the  cartilaginous  part  of  the  Eustachian  tube. 

1,  2,  bent  cartilaginous  plate  ;  3,  muse,  dilatator  tuba?  ;  to  the  left  of  4,  part  of  the  attachment 
of  the  levator  palati  muscle  :  5,  tissue  uniting  the  tube  to  the  base  of  the  skull ;  6  and  7, 
mucous  glands  ;  8,  10,  fat ;  9  to  11,  lumen  of  the  tube  ;  12,  connective  tissue  on  the  lateral 
aspect  of  the  tube. 


near  the  pharynx,  it  is  bounded  partly  by  a  bent  piece  of  cartilage 
(fig.  268,  l,  2),  partly  by  fibrous  tissue.  The  latter  contains  numerous 
mucous  glands  (6,  7),  which  open  into  the  tube,  and  on  the  outer  side 
a  band  of  muscular  tissue  (3)  which  joins  the  tensor  palati.  The  epithe- 
lium is  ciliated. 


232  THE   ESSENTIALS  OF  HISTOLOGY 


LESSON   XLII. 

STRUCTURE   OF  THE  LABYRINTH. 

1.  Sections  across  one  of  the  membranous  semicircular  canals  of  a  fish 
(skate). 

2.  Longitudinal  sections  through  the  ampulla  of  a  semicircular  canal 
(skate). 

3.  Vertical  sections  through  the  middle  of  the  cochlea  of  a  mammal. 
The  cochlea  is  put  quite  fresh  into  0*2  per  cent,  chromic  acid  containing 

a  few  drops  of  1  per  cent,  osrnic  acid.     When  decalcified,  it  is  well  washed, 
and  then  placed  in  spirit  for  a  day  or  more. 

In  preparing  sections  of  the  above  three  preparations  it  is  advisable,  in 
order  that  the  epithelium  should  be  kept  in  position,  to  mount  them  by  the 
creosote-shellac  process.  They  may  previously  be  stained  in  bulk  either  by 
alcoholic  magenta  or  borax-carmine. 

4.  Teased  preparations  of  the  auditory  epithelium  of  an  ampulla  or  of  the 
macula  of  the  utricle,  from  the  fish. 

5.  Teased  preparations  of  the  epithelium  of  the  organ  of  Corti  from  the 
guinea-pig. 

Both  4  and  5  are  made  from  osmic  preparations. 

Make  sketches  froin  all  these  preparations  under  the  high  power. 


The  labyrinth,  which  is  the  essential  part  of  the  auditory  organ, 
consists  of  a  complex  membranous  tube  lined  by  epithelium  and  filled 
with  endolymph,  contained  within  a  bony  tube — the  osseous  labyrinth 
— of  corresponding  complexity  of  shape  (figs.  269,  270).  The  mem- 
branous labyrinth  does  not  wholly  fill  the  bony  cavity ;  the  rest  of  the 
space  is  occupied  by  perilymph.  The  membranous  labyrinth  (fig.  269) 
is  composed  of  the  utricle  (u),  and  the  three  semicircular  canals,  each 
with  an  enlargement  or  ampulla  which  opens  into  it,  the  saccule  (s) 
and  the  canal  of  the  cochlea  [c.  c.) 

The  branches  of  the  auditory  nerve  pass  to  certain  parts  only  of 
the  membranous  labyrinth,  viz.  :  the  maculae  of  the  utricle  and 
saccule  ;  the  cristae  of  the  ampullae,  and  along  the  whole  length  of  the 
canal  of  the  cochlea  (the  shaded  parts  in  fig.  269). 


STRUCTURE   OF   THE   LABYRTN'TH 


233 


At  these  places  the  lining  epithelium  is  specially  modified  to  form 
a  sensory  or  nerve-epithelium ;  elsewhere  it  is  a  simple  pavement- 
epithelium. 


1/7-tA 


Fig.  2G9. — Plan  of  the  right  mem- 
branous LABYRINTH  VIEWED  FROM 
THE   MESIAL    ASPECT.       2j 

u,  utricle,  with  it?  macula  and  the  three 
semicircular  canals  with  their  ampullae; 
*,  saccule  ;  ag.  v.  aquasductus  vestibuli ;  s.e. 
saecus  endolymphaticus  :  e.  >:  canalis  re- 
unieus  ;  c.c.  caual  of  the  cochlea. 


Fig.  270. — View  of  the  interior  of 
the  left  osseous  labyrinth.     2* 

The  bony  wall  of  the  labyrinth  is  removed 
superiorly  and  externally.  1,  fovea  hemi- 
elliptica:  2,foveahemisphaerica;  3.  common 
opening  of  the  superior  and  posterior  semi- 
circular canals ;  4,  opening  of  the  aqueduct 
of  the  vestibule ;  5,  the  superior,  6,  the 
posterior,  and  7,  the  external  semicircular 
canals;  8,  spiral  tube  of  the  cochlea;  9, 
scala  tympani ;  10,  scala  vestibuli. 


The  membranous  semicircular  canals  and  the  utricle  and  saccule 
are  composed  of  fibrous  tissue,  which  is  adherent  along  one  side  to  the 
endosteum  of  the  bony  canal ;  from  the  opposite  side  bands  of  fibrous 
tissue  pass  across  the  perilymph.  Within  the  fibrous  membrane  is  a 
thick  clear  tunica  propria,  which,  in  the  semicircular  canals,  forms 
papillary  elevations  in  the  interior  of  the  tube  (figs.  271,  272). 

The  places  of  entrance  of  the  nerve-fibres  into  the  ampulla?-  are 
marked  by  a  transverse,  inwardly  projecting  ridge  {crista),  in  the 
saccule  and  utricle  by  a  thickening  of  the  tunica  propria  (macula). 
The  epithelium  at  these  places  is  formed  of  columnar  cells  (fig.  273;, 
which  are  surmounted  by  long,  stiff,  tapering  hairs  {auditor)/  hairs, 
fig.  273,  h),  and  to  these  hair-cells  the  axis-cylinders  of  the  nerve-fibres 
pass  directly  (fig.  274)  ;  they  are  therefore — like  the  rod-  and  cone- 
elements  of  the  retina,  the  bipolar  cells  of  the  olfactory  membrane,  and 
the  gustatory  cells  of  the  taste-buds — sensory  or  neural  epithelium-cells. 
Between  them  are  a  number  of  thin  and  somewhat  rigid  nucleated 
cells  [fibre-cells  of  Eetzius,  fig.  274,/),  which  rest  upon  the  basement- 
membrane,  and  are  connected  at  their  free  extremity  with  a  cuticular 
membrane,  through  which  the  auditory  hairs  project. 

The  auditory  hairs  do  not  project  free  into  the  endolymph,  but 
into  a  soft  mucus-like  substance,  of  a  dome-like  form,  in  the  ampullae 
(fig.  273),  and  which  in  the  saccule  and  utricle  has  a  mass  of  calcareous 
particles  (otoliths)  embedded  in  it. 


234 


THE   ESSENTIALS   OF   HISTOLOGY 


Fig.  271. — Section  of  one  of  the  human  semicircular  canals.    (Magnified.) 

1,  osseous  wall ;  2,  fibrous  bands  with  included  blood-vessels,  united  at  3  with  the  periosteum ; 
4,  membranous  canal  with  its  three  layers;  5,  short  fibrous  bands  (with  intervening 
spaces)  uniting  the  membranous  canal  firmly  to  the  neriosteum  ;  6,  union  of  its  outermost 
layer  with  the  periosteum. 


Fig.  272.— Section  of  membranous  semicircular  canal.    (Much  magnified.) 

1,  outer  fibrous  laver;  2,  tunica  propria ;  3,  6,  papilliform  projections  with  epithelial  covering; 
5,  fixed  side  of  the  canal,  with  very  thin  tunica  propria  without  papilke;  7,  fibrous  bands 
passing  to  periosteum. 


STRUCTURE   OF  THE   COCHLEA 


235 


Fig.  273. — Longitudinal  section  of  an  ampulla  through  the  crista  acustica. 

amp,  cavity  of  the  ampulla;  sec,  semicircular  canal  opening  out  of  it;  c,  connective  tissue 
attached  to  the  wall  of  the  .nembranous  ampulla  and  traversing  the  perilymph ;  e,  e,  flattened 
epithelium  of  ampulla;  h,  auditory  hairs  projecting  from  the  columnar  cells  of  theauditory 
epithelium  into  the  cupula,  tup.  term. ;  v,  blood-vessels  ;  n,  nerve-fibres  entering  the  base  of 
the  crista  and  passing  into  the  columnar  cells. 


Fig.  274. — Auditory  epithelium  from  the  macula  acustica  of  the  saccule 
of  an  alligator.     (  Highly  magnified.) 

c,e,  columnar  hair-cells ;/./',  fibre-cells ;  n,  nerve-fibre,  losing  its  medullar;  sheath  and  passing 
to  terminate  in  the  columnar  auditory  cells  ;  h,  auditory  hair  ;  h',  base  of  auditory  hairs, 
split  up  into  fibrils. 


236 


THE  ESSENTIALS   OF  HISTOLOGY 


The  cochlea  consists  of  a  bony  tube  coiled  spirally  around  an  axis, 
which  is  known  as  the  columella  (fig.  275).  The  tube  is  divided 
longitudinally    by  a  partition  which  is  formed  partly  by  a  projecting 


Fig.  275.— Vertical  section  of  the  cochlea  of  a  calf. 


n      sp.l 


Fig.  276.— Vertical  section  of  the  first  turn  of  the  human  cochlea. 

(Retzius.) 

s.r.  «cala  vestibuli:  iJ.  Bcala  tympani;  h.f.  r-annl  of  the  cochlea:  sp.l.  spiral  lamina:  n. 
nerve-fibres;  I.sp.  spiral  ligament;  sir.c.  stria  vascularis ;  t.tp,  spiral  groove-;  A',  section  of 
Reissner's  membrane:  /.  Umbos  laminae  spiralis;  MA.  membrana  tectoria;  AC.  tunnel  of 
Corti ;  b.m.  basilar  membrane  ;  h.i.,  h.f..  internal  and  external  hair-cells. 


lamina  of  bone  (spiral  lamina),  partly  by  a  flat  membrane  (basilar 
membrane),  into  two  parts  or  scales;  the  upper  (supposing  the  cochlea 
resting  base  downwards)  being  termed  the  scala  vestibuli  (fig.  276,  s.v.) 


STRUCTURE   OF   THE   COCHLEA  237 

the  lower  the  scala  tympani  (s.t.) ;  the  latter  is  closed  at  its  larger 
end  by  the  membrane  of  the  fenestra  rotunda.  The  scahe  are  lined  by 
endosteum,  and  are  filled  with  perilymph,  continuous  with  that  of  the 
rest  of  the  osseous  labyrinth  at  the  commencement  of  the  scala  vestibuli ; 
they  communicate  at  the  apex  by  a  small  opening,  the  hclicotrema. 

The  scala  vestibuli  does  not  occupy  the  whole  of  that  part  of  the 
bony  tube  of  the  cochlea  which  is  above  the  partition.  Its  outer  third 
is  cut  off  by  a  delicate  connective-tissue  membrane  (membrane  of 
Eeissner,  fig.  276,  B),  which  springs  from  near  the  end  of  the 
spiral  lamina,  and  passes  upwards  and  outwards  to  the  outer  wall,  thus 
separating  a  canal  (DC)  triangular  in  section,  which  is  lined  by  epithe- 
lium, and  represents  the  membranous  labyrinth  of  the  cochlea  (canal 
of  the  cochlea). 

Canal  of  the  cochlea.  The  floor  of  the  canal  of  the  cochlea  is 
formed  (1)  of  the  extremity  of  the  spiral  lamina,  which  is  thickened 
above  by  a  peculiar  kind  of  connective  tissue,  forming  an  overhanging 
projection  known  as  the  limbics  (fig.  270,  I) ;  (2)  of  the  basilar  mem- 
brane (b.m.t,  which  stretches  across  from  the  end  of  the  bony  lamina 
to  the  outer  wall,  and  is  attached  to  this  by  a  projection  of  reticular 
connective  tissue  termed  the  spiral  ligament  \l.sp.) 

The  basilar  membrane  is  composed  of  stiff,  straight  fibres,  which 
extend  from  within  out,  and  themselves  rest  on  a  homogeneous  stratum. 
It  is  covered  below  by  a  layer  of  connective  tissue  continuous  with  the 
endosteum  of  the  scala  tympani ;  above  the  modified  epithelium  which 
forms  the  organ  of  Corti  rests  upon  it.  It  becomes  gradually  broader 
in  the  upper  turns  of  the  cochlea  (rather  more  than  twice  as  broad  in 
the  uppermost  as  in  the  lowermost  turn),  and  its  constituent  fibres 
become  therefore  gradually  longer. 

The  organ  of  Corti  consists  of  the  following  structures  : 

1.  The  rods  of  Corti,  two  series  (inner  and  outer)  of  stiff,  striated 
fibres  of  a  peculiar  shape,  the  inner  rods  somewhat  like  a  human  ulna, 
the  outer  like  a  swan's  head  and  neck  (fig.  277).  They  rest  by  one  ex- 
tremity i  the  foot)  on  the  basilar  membrane  a  short  distance  apart,  and 


Fig.  277. — A  r.uic  <>f  bods  of  Cohti,  from  thk.  rabbit's  cochlea,  i>'  side 
VIEW.     (Highly  magnified.) 

b,  b,  basilar  membrane  ;  i.r.  inner  roil :  e.r.  outer  rod.    The  nucleated  protoplasmic  masses  at 
the  feet  are  also  shown. 

are  inclined  towards  one  another,  their  larger  ends  ( heads  i  being  jointed 
together  ;  the  series  of  rods  thus  enclose  a  sort  of  tunnel,  the  floor  of 
which  is  formed  by  a  part  of  the  basilar  membrane.     Close   to  their 


238 


THE   ESSENTIALS   OF  HISTOLOGY 


feet  may  usually  be  seen  the  remainder  of  the  cells  from  which  they 
have  been  formed.  The  inner  rods  are  narrower  and  rather  more 
numerous  than  the  outer.  Each  outer  rod  has  a  process  which  extends 
outwards  and  is  known  as  the  phalangeal  process.  This  forms  part 
of— 

2.  A  reticular  lamina  (fig.  279,  l.r.),  which  is  a  cuticular  structure 
extending  like  a  wire-net  over  the  outer  epithelium-cells  of  the  organ 
of  Corti,  and  is  composed  of  two  or  three  series  of  stiff  fiddle-shaped 
rings  (phalanges)  cemented  together  in  such  a  manner  as  to  leave 
square  or  oblong  apertures  through  which  the  hair-cells  (see  below) 
project. 

3.  The  outer  hair-cells  placed  external  to  the  rods  of  Corti.  These 
are  epithelium-cells  of  columnar  shape,  arranged  in  three  or  four  series 


b— 


~.-3 


Fig.  278. — Section  of  the  organ  of  Corti  of  the  dog.     sqq 

a,  «'.  end  of  spiral  lamina ;  6,  c,  middle  (homogeneous)  layer  of  the  basilar  membrane  :  u,  ves- 
tibular (striated  >  layer:  (.tympanal  (connective-tissue)  layer  ;  d,  blood-vessel  : /,  nerves 
in  spiral  lamina  ;  ./.  epithelium  of  spiral  groove  ;  h,  nerve-fibres  passing  towards  inner  hair- 
cells,  i,  £  ;  I.  auditory  hairlets  on  inner  hair-cells  ;  /.  /',  lamina  reticularis  ;  m,  heads  of  the 
rods  of  Corti.  jointed  together  ;  n,  base  of  inner  rod-  ;  ,,.  base  of  outer  rod  :  p.  q,  r,  outer 
hair-cells  ;  t,  lower  ends  of  hair-cells  ;  ic,  nerve-fibrils  passing  across  the  tunnel  of  Corti ; 
z,  cells  of  Deiters. 


(fig.  278,  p,  q,  r).  The  free  extremity  of  the  cell  is  surmounted  by  a 
bundle  of  short  auditor)/  hairs,  and  projects  through  one  of  the 
apertures  in  the  reticular  lamina  ;  the  fixed  extremity  is  prolonged 
into  a  stiff  cuticular  process  (fig.  280,  pf),  which  is  attached  to  the 
basilar  membrane.  Between  them  are  other  supporting  cells  which 
are  tapered  in  the  same  manner,  resting  by  their  larger  end  upon  the 
basilar  membrane,  and  prolonged  above  into  a  cuticular  process  which 
is  attached  to  the  reticular  lamina  {cells  of  Deiters,  fig.  278,  z).  They 
are  said  by  Waldeyer  to  be  sometimes  united  with  the  outer  hair-cells, 
so  as  to  form  double  cells. 

4.  The  inner  hair-cells  (fig.  278,  i),  placed  internal  to  the  rods  of 


STRUCTURE   OF   THE   COCHLEA 


239 


Fig.  279.  —  Semi-diagram- 
matic  view  of  part  of 
the  basilar  membrane 
and  tl'xnki.  of  corti  of 
the  rabbit,  from  above 

AND      THE     SIDE.  (Much 

magnified.) 

I.  limbus  ;  Cr.  extremity  or  crest 
of  limbus  with  tooth-like  pro- 
jections ;  b.b.  basilar  membrane; 
sp.l.  spiral  lamina  with,  p, 
perforations  for  transmission  of 
nerve-fibres.  In  part  of  the 
spiral  lamina  here  represented 
the  nerve-fibres  are  left,  and  are 
supposed  to  be  seen  through  the 
upper  layer  of  that  lamina,  con 
verging  to  three  of  the  perfora- 
tions :  to  the  right,  in  the  section 
of  the  lamina,  they  are  shown 
occupyingacaual.orcleft.  in  the 
osseous  substance;  i.r.  fifteen 
of  the  inner  rods  of  Corti ;  h.i. 
their  flattened  heads  seen  from 
above;  e.r.  nine  outer  rods  of 
Corti  :  h.e.  their  heads,  with 
the  phalangeal  processes  ex- 
tending  out  ward  from  them  and 
forming,  with  the  two  rows  of 
phalanges,  the  lamina  reticu- 
lar!-. I.r.  On  the  left  of  the 
figure  the  connective-tissue 
fibres  and  nuclei  of  the  unier- 
most  layer  of  the  basilar  mem- 
brane are  seen  through  the 
upper  layers.  Portions  of  the 
basilar  processes  of  the  outer 
hair-cells  remain  attached  here 
and  there  to  the  membrane  at 
this  part. 


Fig.  280. — An  outer  hate-cell  in  connection  with  its  basilar 
process.    From  the  guinea-pig.     (Highly  magnified.) 

h,  one  or  two  hairlets  which  have  remained  attached  to  the  cell  :  6.  bulged 
lower  end  of  cell  :  p.  basilar  process,  protoplasmic  above,  but  becoming 
cutioular  below  and  slightly  expanded  at  the  extremity,/,  which  is  broken 
away  from  the  basilar  membrane. 


240 


THE   ESSENTIALS   OF  HISTOLOGY 


Corti.  They  form  a  single  series  of  columnar  cells  surmounted  by 
auditory  hairs,  lying  in  close  apposition  to  the  inner  rods. 

The  rest  of  the  epithelium-cells  have  no  important  characteristics. 
They  are  long  and  columnar  next  the  outer  hair-cells,  but  soon  diminish 
in  size,  becoming  cubical,  and  in  this  form  they  are  continued  over 
the  outer  wall  of  the  cochlear  canal.  Here  they  cover  a  very  vascular 
membrane  (stria  vascularis,  fig.  27G,  sir),  which  is  frequently  pigmented ; 
its  capillary  blood-vessels  may  even  penetrate  between  the  epithelium - 
cells.  Internal  to  the  inner  hair-cells  the  epithelium  also  soon  becomes 
cubical ;  it  is  prolonged  in  this  form  over  the  limbus  of  the  spiral 
lamina.  The  epithelium  of  Eeissner's  membrane  is  of  the  pavement 
variety. 

The  membrana  tectoria  Ifig.  276,  M.t.)  is  a  soft,  fibrillated 
structure,  which  is  attached  along  the  upper  surface  of  the  limbus,  and 
lies  like  a  pad  over  the  organ  of  Corti.  It  thins  out  towards  the 
distal  margin,  here  becoming  somewhat  reticular,  and,  according  to 
Eetzius,  attached  to  the  lamina  reticularis.  In  sections  it  usually 
appears  raised  a  short  distance  above  the  auditory  hairs,  but  it  is 
possible  that  it  may  rest  upon  them  during  life. 


Fig.  281. — General  view  of  the  mode  of  distribution  of  the  cochlear  nerve, 
all  the  other  parts  having  been  removed. 


The  fibres  of  the  cochlear  branch  of  the  auditory  nerve  enter  the 
base  of  the  columella,  and  run  in  canals  through  its  substance,  being 
gradually  deflected  outwards  as  they  pass  upwards  into  the  spiral 
lamina,  at  the  base  of  which  they  swell  out  into  a  ganglionic  cord 
(spiral  ganglion i. 

After  traversing  the  spiral  lamina  they  emerge  in  bundles,  and  the 
fibres  then,  having  lost  their  medullary  sheath,  pass  into  the  epithe- 
lium of  the  inner  hair-cell  region.  Here  some  of  them  are  connected 
directly  with  the  inner  hair-cells,  whilst  others  pass  in  the  form  of 
delicate  fibrils  across  the  tunnel  of  Corti,  to  become  connected  with 
the  outer  hair-cells  (fig.  278j. 


APPENDIX. 


General  Methods  of  Preserving  and  Hardening  Tissues  and  Organs.1 — The 
fluids  which  are  most  commonly  used  are  alcohol,  chromic  acid  solution 
(1  in  500),  picric  acid  solution  (saturated),  bichromate  of  potash  solution 
(2  per  cent.),  Midler's  fluid  (bichromate  of  potash  2£  parts  ;  sulphate  of  sod* 
1  part ;  water  100  parts),  and  bichromate  of  ammonia  (2  per  cent.)  The 
following  are  the  methods  of  hardening  the  several  tissues  and  organs  which 
are  found  to  give  the  best  general  results  : — 


Tissue  or  Organ 

Bladder 

Blood-vessels 

Brain 

Elastic  ligament 

Embryos   . 

Eye   . 

Eyelids 

Ganglia 

Heart 

Injected  organs 

Intestine    . 

Kidney 

Lachrymal  gland 

Larynx 

Liver 

Lung 

Mammary  gland 

Marrow  of  bone 

Muscular  tissue,  striated 

„  non-striated 

Nerve 
(Esophagus 
( )vary 
Pancreas    . 
Retina 

Salivary  glands  . 
Sclerotic  and  cornea 
Skin  . 


Hardening  Fluid 

Chromic  acid. 

Alcohol,  or  bichromate  of  potash. 

Bichromate  of  ammonia. 

Bichromate  of  potash. 

Chromic  acid  or  picric  acid. 

Midler's  fluid. 

Alcohol. 

Picric  acid. 

Alcohol,  or  bichromate  of  potash. 

Alcohol. 

Distend  with  chromic  acid. 

Bichromate  of  potash. 

Alcohol. 

Chromic  acid. 

Bichromate  of  potash. 

Distend  with  chromic  acid. 

Alcohol. 

Alcohol. 

Bichromate  of  potash. 

Chromic  acid. 

Picric  acid. 

Distend  with  chromic  acid. 

Chromic  acid. 

Alcohol. 

Midler's  fluid. 

Alcohol. 

Alcohol,  or  Midler's  fluid. 

Alcohol. 


1  Methods  of  preparation  required  for  special  purposes  are  given  in  the  Lessons. 

R 


242  THE  ESSENTIALS   OF  HISTOLOGY 

Tissue  or  Organ  Hardening  Fluid 


Spinal  cord 
Spleen 
Stomach    . 

Suprarenal  capsule    . 

Tendon  and  ligament 

Testis 

Thymus  gland   . 

Thyroid  gland    . 

Tongue 

Tonsils 

Trachea 

Ureter 

Uterus 


Bichromate  of  ammonia. 

Bichromate  of  potash. 

Distend  with  chromic  acid  or  with 

alcohol. 
Alcohol. 
Alcohol. 
Alcohol. 
Alcohol. 
Alcohol. 

Bichromate  of  potash. 
Alcohol. 
Chromic  acid. 
Chromic  acid. 
Chromic  acid. 


Tissues  to  be  hardened  in  alcohol  may  either  be  placed  at  once  in  strong 
spirit  (90  per  cent,  alcohol),  or  the  hardening  may  be  effected  gradually,  the 
tissue  being  placed  first  in  weak  spirit  (50  per  cent.)  for  twenty-four  hours, 
then  in  somewhat  stronger,  and  finally  in  strong  spirit  or  absolute  alcohol. 
They  are  ready  for  cutting  after  having  been  twenty-four  hours  in  strong 
spirit. 

For  tissues  that  are  to  be  hardened  in  l  per  cent,  chromic  acid,  an  immer- 
sion of  from  7  to  14  days  is  generally  necessary  ;  they  may  then  be  washed 
with  water,  and  placed  in  alcohol  for  preservation  and  to  complete  the  pro- 
cess of  hardening. 

Organs  placed  in  bichromate  of  potash  or  Midler's  fluid  are  ready  for 
sections  in  a  fortnight  or  three  weeks ;  they  may,  however,  be  left  for  a  much 
longer  time  in  those  fluids  without  deterioration.  With  picric  acid  the 
hardening  process  is  generally  complete  in  two  or  three  days;  the  organs 
should  then  be  washed  for  some  hours  under  a  tap  and  transferred  to  spirit. 

The  hardening  of  the  brain  and  spinal  cord  in  bichromate  of  ammonia 
takes  three  or  four  weeks.  These  organs  should  not  be  left  too  long  in  the 
solution,  since  they  are  apt  to  become  brittle,  but  sections  should  be  prepared 
from  them  as  soon  as  ready. 

In  no  case  should  the  pieces  of  tissue  to  be  hardened  be  too  thick  for  the 
fluid  readily  to  penetrate  to  every  part. 

Embedding  of  Hardened  Tissues,  and  Preparation  of  Sections.— Sections  are 
most  advantageously  made  with  some  form  of  microtome.  It  is  generally 
needful  to  support  the  hardened  tissue  whilst  it  is  being  cut,  and  with  this 
object  it  is  embedded  in  some  fatty  or  other  substance  which  is  applied  to  it 
in  the  fluid  condition  and  becomes  solid  on  standing.  The  embedding  sub- 
stance can  either  simply  enclose  the  tissue,  or  the  tissue  may  be  soaked  in 
it :  the  latter  method  is  the  one  most  commonly  employed. 

The  embedding  substance  chiefly  used  is  paraffin. 

Embedding  in  paraffin. — Before  being  soaked  in  melted  paraffin,  the 
piece  of  tissue  is  stained  with  borax-carmine  or  hematoxylin,  dehydrated  by 
absolute  alcohol,  and  is  then  soaked  in  turpentine.  From  turpentine  it  is 
transferred  to  melted  paraffin,  which  should  not  be  too  hot.  and  soaked  in  this 
for  an  hour  or  more,  according  to  thickness.  It  is  then  placed  in  any  desired 
position  in  a  paper  tray  or  on  the  microtome  and  surrounded  by  melted 


APPENDIX  243 

paraffin.  When  cold,  thin  sections  can  be  cut,  the  paraffin  dissolved  out  by 
turpentine,  and  the  sections  mounted. 

Preparation  of  frozen  sections. — The  bichromate  solutions  are  the  best 
fluids  to  use  for  preserving  tissues  which  are  to  be  frozen  in  place  of  being 
embedded.  The  tissue  in  such  cases  should  not  be  put  into  alcohol,  but 
merely  requires  to  be  dipped  in  strong  gum  before  being  placed  upon  the 
freezing  microtome.  Portions  of  the  central  nervous  system  need  to  be 
soaked  in  giun  to  which  a  little  syrup  has  been  added. 

Staining  and  mounting  of  sections. — The  fluids  most  commonly  employed 
for  the  staining  of  sections  are  : — 1.  A  dilute  watery  solution  of  hematoxylin 
and  alum  ;  2.  A  solution  of  carmine  ;  3.  A  solution  of  picro-carminate  of  am- 
monia. The  time  of  immersion  in  the  staining  fluid  varies  according  to  the 
strength  of  the  fluid  and  the  mode  by  which  the  tissue  has  been  hardened. 
The  necessity  of  staining  sections  may  be  avoided  if  the  piece  of  tissue  is 
stained  in  bulk  before  embedding.  For  this  purpose  a  carmine  solution  is 
mostly  used,  on  account  of  its  penetrative  power,  that  known  as  borax-carmine 
bein?  the  best.  The  tissue  must  be  left  in  it  for  twenty-four  hours  or  more, 
and  then  placed  in  acidulated  alcohol.  An  alcoholic  solution  of  magenta  can 
be  used  for  staining  in  bulk ;  from  this  the  tissue  goes  into  a  small  quantity 
of  oil  of  cloves  or  into  turpentine,  and,  after  being  soaked  with  this,  into  the 
melted  paraffin. 

If  the  tissues  have  not  been  stained  in  bulk,  the  following  is  the  order  of 
transference  of  the  sections  (they  are  supposed,  if  cut  from  paraffin,  to  have 
been  freed  from  this  by  immersion  in  turpentine)  :— 

1.  From  turpentine  to  absolute  alcohol  (5  minutes). 

2.  From  alcohol  to  distilled  water  iA  minute). 

3.  From  distilled  water  to  hematoxylin  or  carmine  (5  minutes  or  more). 

4.  From  hematoxylin  to  distilled  water  (h  minute). 

5.  From  distilled  water  to  alcohol  (2  or  3  minutes). 

6.  From  alcohol  to  oil  of  cloves  il  minute). 

7.  From  oil  of  cloves  to  Canada  balsam. 

If  the  tissues  have  already  been  stained  in  bulk,  the  sections  are  simply 
mounted  in  Canada  balsam  after  the  paraffin  used  for  embedding  has  been 
dissolved  away  from  them  in  turpentine. 

Creosote-shellac  method  of  mounting. — Friable  sections,  such  as  sections 
of  small  embryos,  and  ribands  of  sections  such  as  are  cut  with  many  micro- 
tomes, are  mounted  in  the  following  way  : — The  slide  is  smeared  with  a  solu- 
tion of  shellac  in  creosote,  the  sections  are  placed  in  this  and  warmed  so  as  to 
melt  their  paraffin.  They  are  thus  fixed  by  the  shellac,  and  the  slide  can  be 
immersed  in  turpentine  to  remove  the  paraffin,  and  the  sections  then  covered 
in  Canada  balsam.  For  this  method  the  tissue  should  always  have  been  pre- 
viously stained  in  bulk. 

Solutions  employed  for  Staining:  — 1.  Solution  of  hatmatoxyhn  in-icatcr. — 
Rub  together  in  a  mortar  10  grammes  of  powdered  alum  and  5  grammes  of 
extract  of  hematoxylin  with  25  cubic  centimeters  of  70  per  cent,  alcohol, 
gradually  adding  100  cubic  centimeters  of  distilled  water.  Decant  into  a 
bottle  and  add  a  drop  or  two  of  ammonia.  Let  the  mixture  stand  a  few 
days,  occasionally  shaking  it.  For  staining,  add  two  or  three  drops  to  a 
watch-glass  full  of  distilled  water,  and  filter  if  necessary. 

2.  Grrenacher'8  hematoxylin. — To  150  cubic  centimeters  of  a  saturated 


244  THE   ESSENTIALS   OF   HISTOLOGY 

solution  of  alum  in  water,  add  4  cubic  centimeters  of  saturated  solution  of 
hematoxylin  in  alcohol.  Let  the  mixture  stand  8  days,  then  decant,  and 
add  25  cubic  centimeters  of  glycerine,  and  25  cubic  centimeters  of  methylic 
alcohol. 

3.  Kleinenberg'e  hcematoxylin. — This  serves  better  for  staining  in  bulk. 
Saturate  70  per  cent,  alcohol  hist  with  calcium  chloride  and  then  with  alum, 
and  after  filtration  add  six  to  eight  volumes  of  70  per  cent,  alcohol. 

Take  a  freshly  prepared  saturated  solution  of  hematoxylin  in  absolute 
alcohol,  and  add  it  drop  by  drop  to  the  above  mixture  until  it  is  of  a  distinct 
purplish  colour. 

This  solution  improves  on  keeping.  It  may  if  necessary  be  diluted  with 
more  of  the  mixture 

"When  hematoxylin  solutions  become  red  instead  of  blue,  a  trace  of 
ammonia  will  restore  the  requisite  colour. 

4.  Carminute  of  ammonia. — Prepared  by  dissolving  carmine  in  ammonia 
and  allowing  the  excess  of  ammonia  to  escape  by  slow  evaporation.  The 
salt  should  be  allowed  to  dry  and  be  dissolved  in  water  as  required. 

5.  Picro-carminate  of  ammonia  (pier o -carmine). — To  a  saturated  solution 
of  picric  acid  add  a  strong  ammoniacaJ  solution  of  carmine,  until  a  precipitate 
begins  to  form.  Evaporate  on  the  water-bath  to  |th  ;  filter  from  the  sedi- 
ment and  evaporate  the  filtrate  to  dryness.  Make  a  5  per  cent,  solution  of 
the  residue,  diluting  further  as  required. 

6.  Borax-carmine. — a.  Dissolve  4  grammes  borax  and  3  grammes 
carmine  in  100  cubic  centimeters  of  warm  water.  Add  100  cubic  centimeters 
of  70  per  cent,  alcohol,  filter  and  let  stand.  This  solution  improves  on  keep- 
ing.    It  is  useful  for  staining  in  bulk. 

/3.  Boil  0-5  gramme  carmine  and  1  gramme  borax  in  100  cubic  centi- 
meters water.  Filter  and  add  acetic  acid  drop  by  drop  until  the  original 
violet  colour  becomes  crimson  ;  then  filter  once  more.  This  solution  is  used 
for  staining  sections. 

After  staining  with  borax-carmine,  the  tissue  should  in  all  cases  be  placed 
in  70  per  cent,  alcohol  containing  5  drops  of  hydrochloric  acid  to  100  cubic 
centimeters. 

7.  Magenta. — This  may  be  kept  in  solution  in  alcohol  (0*5  to  1  per  cent.) 
For  fresh  tissues  and  for  sections  to  be  mounted  in  glycerine,  an  excellent 
staining  fluid  is  obtained  by  adding  one  or  two  drops  to  a  watch-glass  of  water. 
For  sections  to  be  mounted  in  Canada  balsam  a  solution  in  oil  of  cloves  is 
used.  This  is  best  made  by  adding  a  drop  of  the  alcoholic  solution  to  a  little 
oil  of  cloves  in  a  watch-glass  :  the  sections  after  being  stained  are  washed 
in  spirit  of  turpentine. 

8.  Gentian  violet. — Mix  20  cubic  centimeters  water  with  10  cubic  centi- 
meters alcohol  and  10  cubic  centimeters  glycerine,  and  add  to  the  mixture 
10  drops  of  a  1  per  cent,  solution  of  gentian  violet  in  alcohol  and  10  drops 
of  a  25  per  cent,  solution  of  formic  acid  in  water. 

This  solution  gives  excellent  results  with  fresh  tissues,  especially  with 
epithelium. 

9.  Safranin. — A  saturated  alcoholic  solution  is  used  for  staining  cell- 
nuclei.  The  tissue  elements  having  been  fixed  by  dilute  chromic  acid  or  by 
alcohol,  small  shreds  or  thin  sections  are  placed  for  12  to  24  hours  in  a  little 
of  the  solution,  mixed  with  half  its  bulk  of  water.  The  shreds  are  rinsed  in 
absolute  alcohol  (which  must  contain  no  trace  of  free  acid)  until  the  colour  is 


APPENDIX  245 

washed  out  from  everj'thing  except  the  nuclei ;  they  are  then  at  once  trans- 
ferred to  turpentine,  and  from  this  are  mounted  in  Canada  balsam. 

10.  Aniline  blue-black. — Dissolve  1  gramme  of  aniline  blue-black  in  a 
mixture  of  30  parts  of  water  with  20  of  alcohol.  This  serves  for  staining  the 
central  nervous  system  either  in  bulk  or  in  sections. 

11.  Staining  with  chloride  of  gold. — a.  Cohnheim's  method. — Place  the 
fresh  tissue  for  from  30  to  60  minutes  in  j  per  cent,  solution  of  chloride  of 
<_r •  >  1  < I  :  then  wash  and  transfer  to  a  large  quantity  of  water  just  acidulated 
with  acetic  acid.     Keep  for  2  or  3  days  m  the  light  in  a  warm  place. 

3.  LovriVi  method. — Place  small  pieces  of  the  fresh  tissue  in  a  mixture 
of  1  part  of  formic  acid  to  2  to  4  parts  of  water  for  h  to  1  minute  ;  then  in 
1  per  cent,  chloride  of  gold  solution  for  10  to  15  minutes  ;  then  back  again  into 
the  formic  acid  mixture  for  24  hours  and  then  into  pure  formic  acid  for  24 
hours  more.  After  removal  from  the  gold,  and  whilst  in  the  acid,  the  tissue 
must  be  kept  in  the  dark. 

y.  Ranvier's  method. — Immerse  in  lemon-juice  for  5  to  10  minutes,  then 
wash  with  water  and  place  in  1  per  cent,  gold  chloride  solution  for  20  minutes. 
Then  treat  either  as  in  Cohnheim's  or  in  Lowit's  method. 

12.  Staining  with  nitrate  of  silver. — Wash  the  fresh  tissue  with  distilled 
water;  immerse  in  ^  to  1  per  cent,  nitrate  of  silver  solution  for  5  to  10 
minutes  ;  rinse  with  distilled  water  and  expose  to  bright  sunlight  either  in 
water,  alcohol,  or  glycerine. 

Mounting  Solutions  : — 1.  Saline  solution. — A  0-6  per  cent,  solution  of 
common  salt  is  used  in  place  of  serum  for  mounting  fresh  tissues  for  imme- 
diate examination. 

2.  A  mixture  of  glycerine  and  water  in  equal  parts. 

3.  Farrant's  solution. — Take  a  mixture  of  equal  parts  of  glycerine  and 
saturated  watery  solution  of  arsenious  acid,  and  stir  guru  arabic  with  it  until  a 
thick  syrupy  rluid  is  formed.     Filter. 

4.  Canada  balsam,  from  which  the  volatile  oils  have  been  driven  off  by 
heat,  dissolved  in  benzole. 


LEA    BROTHERS    &    CO.'S 

[Late  HENRY  C.  LEA'S  SON  &  CO.) 

CLASSIFIED   CATALOGUE 

OP 

MEDICAL  AND  SURGICAL 

PUBLICATIONS. 


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LEA    BROTHERS  &   CO. 
Nos.  706  and  708  Sansom  St.,  Philadelphia,  September,  1885. 


PROSPECTUS    FOR    1885. 

A   WEEKLY    MEDICAL    JOURNAL. 


SUBSCRIPTION    RATES. 

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The  American  Journal  op  the  Medical  Sciences         .       Five  Dollars. 

COMMUTATION    RATES. 

The  Medical  News  \      Nine  Dollars  per 

The  American  Journal  of  the  Medical  Sciences    J      annum,  in  advance. 

THE  MEDICAL  NEWS. 

A  National  Weekly  Medical  Periodical,  containing  28  to  32  Quarto 
Pages  of  Beading  Matter  in  Each  Issue. 

The  Medicax  News  endeavors  to  render  efficient  assistance  in  the  daily  work 
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2    Lea  Brothers  &  Co.'s  Periodicals — Medical  News,  Am.  Journal. 


THE   MEDICAL   NEWS-WEEKLY. 

(.Continued    from  first  p 

Original  Department  its  columns  are  replete  with  articles  of  the  highest  practical  value; 
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THE  AMERICAN  JOURNAL  of  the  MEDICAL  SCIENCES, 

Edited  by  I.  MINIS  HAYS,  A.  M.,  M.  D., 

Is  published  Quarterly,  on  the  first  days  of  January,  April,  July 

and  October,  each  Number  containing  over  Three  Hundred 

Octavo  Pages,  fully  Illustrated. 

In  his  contribution  to  "A  Century  of  American  Medicine,"  published  in  1876,  Dr. 
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HARTSHOJRNE,  HENRY,  A.  M.,  M.  D.f  LL.  D., 

Lately  Professor  of  Hygiene  in  the  University  of  Pennsylvania. 
A  Conspectus  of  the  Medical  Sciences ;  Containing  Handbooks  on  Anatomy, 
Physiology,  Chemistry,  Materia   Medica,   Practice  of  Medicine,  Surgery  and   Obstetrics. 
Second   edition,  thoroughly  revised   and   greatly  improved.     In   one   large  royal  12mo. 
volume  of  1028  pages,  wit b.  477  illustrations.     Cloth,  $4.25;  leather,  $5.00. 

The  object  of  this  manual  is  to  afford  a  conven-  I  industry  and  energy  of  its  able  editor.— Boston 
lent  work  of  reference  to  students  during  the  brief  Medical  and  Surgical.  Journal,  Sept.  3,  1874. 
moments  at  their  command  while  in  attendance  We  can  Bay.  with  the  strictest  truth,  that  it  is  the 
upon  medical  lectures.  It  is  a  favorable  sign  that  |  best  work  of  the  kind  with  which  we  areacquaint- 
it  has  been  found  necessary,  in  a  short  space  of  ed.  It  embodies  in  a  condensed  form  all  recent 
time,  to  issue  a  new  and  carefully  revised  edition,  contributions  to  practical  medicine,  and  is  there- 
The  illustrations  are  very  numerous  and  unusu-  fore  u-eful  to  every  busy  practitioner  throughout 
ally  clear,  and  each  part  "seems  to  have  received  our  country,  besides  being  admirably  adapted  to 
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a  work  to  be  useful,  not  only  to  students,  but  to  faithfully  and  ably  executed.— Charleston  Medical 
practitioners  as  well.    It  reflects  credit  upon  the    Journal.  April,  1875. 

STUDENTS9  SERIES  OF  HAJSUALS. 

A  Series  of  Fifteen  Manuals,  for  the  use  of  Students  and  Practitioners  of  Medicine 
and  Surgery,  written  by  eminent  Teachers  or  Examiners,  and  issued  in  pocket-size 
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Power's  Human  Physiology,  Clarke  and  Lockwood's  Dissectors'  Manual,  Ralfe's 
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Pepper's  Forensic  Medicine,  and  Curnow's  Medical  Applied  Anatomy.  For  separate 
notices  see  index  on  last  page. 

SERIES  OF  CLINICAL  MANUALS. 

In  arranging  for  this  Series  it  has  been  the  design  of  the  publishers  to  provide  the 
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freely  illustrated  by  chromo-lithographs  and  woodcuts.  The  following  volumes  are 
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M  uroses;  The  following  are  in  active  preparation:  Hutchinson  on 
Syphilis;  Bryant  on  the  Breast;  Morris  on  Sm  ases  of  the  Kidney;  Broadbent 

on  the  Puke;  Owen  on  Surgical  diseases  of  Children;  Lucas  on  Diseases  of  the  Urethra; 
Marsh  on  Diseases  of  the  Joints,  Pick  on  Fractures  and  Dislocations,  and  Ball  on  the 
Rectum  and  Am/.-:.     For  separate  notices  see  index  on  last  page. 

NEILL,  JOHN,  31.  D.,  and  SMITH,  F.  G.,  M.  D.f 

Late  Surgeon  to  the  Penna.  Hospital.  Prof,  of  the  Institutes  of  Med.  in  the  Univ.  of  Penna. 

An  Analytical  Compendium  of  the  Various  Branches  of  Medical 
Science,  for  the  use  and  examination  of  Students.  A  new  edition,  revised  and  improved. 
In  one  large  royal  12mo.  volume  of  <J74  pages,  with  374  woodcuts.    Cloth,  $4;  leather,  $4.75. 

LUDLOW,  J.  L.,  M.  D., 

Consulting  Physician  to  the  Philadelphia  Hospital,  etc. 

A  Manual  of  Examinations  upon  Anatomy,  Physiology,  Surgery,  Practice  of 
Medicine,  Obstetrics,  Materia  Medica,  Chemistry,  Pharmacy  and  Therapeutics.  To  which 
is  added  a  Medical  Formulary.  3d  edition,  thoroughly  revised,  and  greatly  enlarged.  In 
one  12mo.  volume  of  816  pages,  with  370  illustrations.     Cloth,  $3.25;  leather,  $3.75. 

The  arrangement  of  this  volume  in  the  form  of  question  and  answer  renders  it  espe- 
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4  Lea  Brothers  &  Co.'s  Publications — Dictionaries. 

DUjSGLISOJT,  ROBBBY,  3L  D., 

Late  P  '     Heinein  the  Jefferson  Medical  College  of  Philadelphia, 

MEDICAL  LEXICON;  A  Dictionary  of  Medical  Science :  Containing 
a  concise  Explanation  of  the  various  Subjects  and  Terms  of  Anatomy,  Physiology,  Pathol- 
ogy, Hygiene,  Therapeutics,  Pharmacology,  Pharmacy,  Surgery,  Obstetrics,  Medical  Juris- 
prudence and  Dentistry,  Notices  of  climate  and  of  Mineral  Waters,  Formulae  for  Officinal, 
Empirical  and  Dietetic  Preparations,  with  the  Accentuation  and  Etymology  of  the  Terms, 
and  the  French  and  other  Synonymes,  so  as  to  constitute  a  French  as  well  as  an  English 
Medical  Lexicon.  Edited  by  Dkiiard  J.  Dungijson,  M.  D.  In  one  very  large  and 
handsome  royal  octavo  volume  ol  1139  pages.  Cloth,  $6.50;  leather,  raised  hands,  $7.50; 
very  handsome  half  Russia,  raised  hands,  $8. 

The  object  of  the  author,  from  the  outset,  has  not  been  to  make  the  work  a  mere  lexi- 
con or  dictionary  of  terms,  hut  to  afford  under  each  word  a  condensed  view  of  its  various 
medical  relations,  and  thus  to  render  the  work  an  epitome  of  the  existing  condition  of 
medical  science.  Starting  with  this  view,  the  immense  demand  which  has  existed  for  the 
work  has  enabled  him,  in  repeated  revisions,  to  augment  its  completeness  and  usefulness, 
until  at  length  it  has  attained  the  position  of  a  recognized  and  standard  authority  wherever 
the  language  is  spoken.  Special  pains  have  been  taken  in  the  preparation  of  the  present 
edition  to  maintain  this  enviable  reputation.  The  additions  to  the  vocabulary  are  more 
numerous  than  in  any  previous  revision,  and  particular  attention  has  been  bestowed  on  the 
accentuation,  which  will  be  found  marked  on  every  word.  The  typographical  arrangement 
has  been  greatly  improved,  rendering  reference  much  more  easy,  and  every  care  has  been 
taken  with  the  mechanical  execution.  The  volume  now  contains  the  matter  of  at  least 
four  ordinary  octavos. 

A  book  of  which  every  American  ought  to  be  work  has  been  well  known  for  about  forty  years, 
proud.  When  the  learned  author  of  the  work  and  needs  no  words  of  praise  on  our  part  to  reeom- 
passed  away,  probably  all  of  us  feared  lest  the  book  i  mend  it  to  the  members  of  the  medical,  and  like- 
should  not  maintain  its  place  in  the  advancing  ,  wise  of  the  pharmaceutical,  profession.  The  latter 
science  whose  terms  it  defines.  Fortunately,  Dr.  especially  are  in  need  of  a  work  which  gives  ready 
Richard  J.  Dunglison,  having  assisted  his  father  in  and  reliable  information  on  thousands  of  subjects 
the  revision  of  several  editions  of  the  work,  and  '  and  terms  which  they  are  liable  to  encounter  in 
having  been,  therefore,  trained  in  the  methods  pursuing  their  daily  vocations,  but  with  which  they 
and  imbued  with  the  spirit  of  the  book,  has  been  j  cannot  be  expected  to  be  familiar.  The  work 
able  to  edit  it  as  a  work  of  the  kind  should  be  i  before  us  fully  supplies  this  want. — American  Jour- 
edited — to  carry  it  on  steadily,  without  jar  or  inter-     rial  of  Pharmacy,  Feb.  1874. 

ruption,  along  the  grooves  of  thought  it  has  trav-  Particular  care  has  been  devoted  to  derivation 
elled  during  its  lifetime.  To  show  the  magnitude  an(j  accentuation  of  terms.  With  regard  to  the 
of  the  task  which  Dr.  Dunglison  has  assumed  and  latter,  indeed,  the  present  edition  may  be  consid- 
carried  through,  it  is  only  necessary  to  state  that  |  ered  a  complete  "Pronouncing  Dictionary  of 
more  than  six  thousand  new  subjects  have  been  Medical  Science."  It  is  perhaps  the  most  reliable 
added  in  the  present  edition.— Philadelphia  Medical  W0T^  published  for  the  busy  practitioner,  as  itcon- 
Times,  Jan.  3,  1874.  tains  information  upon  every  medical  subject,  in 

About  the  first  book  purchased  bv  the  medical  ;  a  C°™  for  "v**  acc«ssi  «»d  with  a  brevity  as  ad- 
student  is  the  Medical  Dictionary. -  The  lexicon  SJP&?-  U  "  P^ctic^.-Southern  Medical  Record, 
explanatory  of  technical  terms  is  simply  a  sine  qua  ■    °'  ■ 

non.     In  a  science  so  extensive  and  with  such  col-         A  valuable  dictionary  of  the  terms  employed  in 
laterals  a<-  medicine,  it  is  as  much  a  necessity  also     medicine  and  the  allied  sciences,  and  of  the  rela- 
to  the  practising  physician.    To  meet  the  wants  of    tions  of  the  subjects  treated  under  each  head.    It 
students  and  most  physicians  the  dictionary  must     well  deserves  the  authority  and  popularity  it  has 
be  condensed  while  comprehensive,  and  practical     obtained.— British  Med.  Jour.,  Oct.  31,  1874. 
while  perspicacious.     It  was  because  Dunglison's         Few  works  of  this  class  exhibit  a  grander  monu- 
met  these  indications  that  it  became  at  once  the  ,  ment  of  patient  research  and  of  scientific  lore. — 
dictionary  of  general  use  wherever  medicine  was     London  Lanct ',  May  13,  1875. 
Btudied  in  the  English  language.    In  no  former        Dunglison's  Dictionary  is  incalculably  valuable, 
revision  have  the  alteration-  and  additions  been     an,i  indispensable  to  every  practitioner  of  medi- 
sogreat.    The  chief  terms  have  been  set  in  black     cine,   pharmacist  and   dentist.—  Western    L 
letter,  while  the  derivatives  follow  in  small  caps;     March    L874 

anarrangement  which  greatly  facilitatesreference.     '   ,,  ,,a's  the  rare  merit  thatitcertainly  has  no  rival 
mnatl  Lancet  and  Chmc,  .Ian.  10,  L874.  jn  t||f.  English  language  for  accuracy  and  extent  of 

As  a  standard  work  of  reference   Dunglison's  :  references. — London  Medical  Uazette. 


BTOBBYJV,  RICHARB  B.,  31.  B. 

A  Dictionary  of  the  Terms  Used  in  Medicine  and  the  Collateral 
Sciences.  Devised,  with  numerous  additions,  by  Isaac  Hays,  M.  D.,  late  editor  of 
The  American  Journal  of  the  Medical  Sciences.  In  one  large  royal  12mo.  volume  of  520 
double-col  mailed  pages.     Cloth,  $1.50;  lea  ther,  §2.00. 

It  i  1:  of  definitions  we  have,  and  ought  always  to  be  upon  the  student's  table  — Southern 

Medical  and  Surgical  Journal. 

ROBWBBB,  G.  F.,  F.  B.  A.  S.,  F.  C.  S., 

Natural  Science  at  Clifton  College,  Emjland. 
A  Dictionary  of  Science:  Comprising  Astronomy,  Chemistry,  Dynamics,  Elec- 
tricity. Heat,  Hydrodynamics,  Hydrostatics,  Light  Magnetism,  Mechanics,  Meteorology, 
Pneumatics,  Sound  and  Statics.  Contributed  by  J.  T.  Bottomley,  M.A.,  F.C.S.,  "William 
Crookes,  F.K.S.,  F.C.S.,  Frederick  Guthrie,  DA.,  Ph.D.,  R.  A.  Proctor,  B.A.,  F.R.A.S., 
G.  F.  Rodwell,  Editor,  Charles  Tomlinson,  F.D.S.,  F.C.S.,  and  Diehard  Wornell,  M. A., 
B.Sc.  Preceded  by  an  Essay  on  the  History  of  the  Physical  Sciences.  In  one  handsome 
octavo  volume  of  70-J  pages,  with  143  illustrations,     (loth,  $5.00. 


Lea  Brothers  &  Co.'s  Publications — Anatomy.  5 

GRAY,  HENRY,  F.  R.  8., 

Lecturer  on  Anatomy  at  St.  George's  Hospital,  London. 

Anatomy,  Descriptive  and  Surgical.  The  Drawings  by  H.  V.  Carter,  M.  D., 
and  I>r.  Wkst.uacott.  The  dissections  jointly  by  the  Author  and  Dr.  Carter.  With 
an  Introduction  on  General  Anatomy  and  Development  by  T.  Holme*,  M.A.,  Surgeon  to 
St.  George's  Hospital.  Edited  by  T.  Pickering  Pick,  F.  B.  C.  S.,  Surgeon  to  and  Lecturer 
on  Anatomy  at  St.  George's  Hospital,  London,  Examiner  in  Anatomy,  Royal  College  of 
Surgeons  of  England.  A  new  American  from  the  tenth  enlarged  and  improved  London 
edition.  To  which  is  added  the  second  American  from  the  latest  English  edition  ot 
Landmarks,  Medical  and  Surgical,  by  Luther  Holdkn,  F.  R.  C.  S.,  author  of 
"Human  Osteology,"  "A  Manual  of  Dissections,"  etc.  In  one  imperial  octavo  volume 
of  L023  pages,  with  564  large  and  elaborate  engravings  on  wood.  Cloth,  $6.00 ;  leather, 
$7.00 ;  very  handsome  half  Russia,  raised  bands,  $7.50. 

This  work  covers  a  more  extended  range  of  subjects  than  is  customary  in  the  ordinary 
text-bonks,  giving  not  only  the  details  necessary  for  the  student,  but  also  the  application  to 
those  details  to  the  practice  of  medicine  and  surgery.  It  thus  forms  both  a  guide  for  the 
learner  and  an  admirable  work  of  reference  for  the  active  practitioner.  The  engravings 
form  a  special  feature  in  the  work,  many  of  them  being  the  size  of  nature,  nearly  all 
original,  and  having  the  names  of  the  various  parts  printed  on  the  body  of  the  cut,  in 
place  of  figures  of  reference  with  descriptions  at  the  foot.  They  thus  form  a  complete  and 
splendid  series,  which  will  greatly  assist  the  student  in  forming  a  clear  idea  of  Anatomy, 
and  will  also  serve  to  refresh  the  memory  of  those  who  may  find  in  the  exigencies  of 
practice  the  necessity  of  recalling  the  details  of  the  dissecting-room.  Combining,  as  it 
does,  a  complete  Atlas  of  Anatomy  with  a  thorough  treatise  on  systematic,  descriptive 
and  applied  Anatomy,  the  work  will  be  found  of  great  service  to  all  physicians  who  receive 
students  in  their  offices,  relieving  both  preceptor  and  pupil  of  much  labor  in  laying  the 
groundwork  of  a  thorough  medical  education. 

Landmarks,  Medical  and  Surgical,  by  the  distinguished  Anatomist,  Mr.  Luther  Holden, 
has  been  appended  to  the  present  edition  as  it  was  to  the  previous  one.  This  work  gives 
in  a  clear,  condensed  and  systematic  way  all  the  information  by  which  the  practitioner  can 
determine  from  the  external  surface  of  the  body  the  position  of  internal  parts.  Thus 
complete,  the  work,  it  is  believed,  will  furnish  all  the  assistance  that  can  be  rendered  by 
type  and  illustration  in  anatomical  study. 

This  well-known  work  comes  to  us  as  t!io  latest  There  is  probably  no  work  used  so  universally 
American  from"  the  tenth  English  edition.  As  its  by  physicians  and  medical  students  as  this  one. 
title  indicates,  it  has  passed  through  many  hands  It  is  deserving  of  the  confidence  that  they  repose 
and  has  received  many  additions  and  revisions,  in  it.  If  the  present  edition  is  compared  with  that 
The  work  is  not  susceptible  of  more  improvement,  issued  two  years  ago,  one  will  readily  see  how 
Taking  it  all  in  all,  its  size,  manner  of  make-up,  much  it  has  been  improved  iu  that  time.  Many 
its  character  and  illustrations,  its  general  accur-  j  pages  have  been  added  to  the  text,  especially  in 
a  -v  of  description,  its  practical  aim,  and  its  per-  those  parts  that  treat  of  histology,  and  many  new 
spicuity  of  style,  it  is  the  Anatomy  best  adapted  to  cms  have  been  introduced  and  old  ones  modified, 
the  wants  of  the  student  and  practitioner. — Medical  — Journal  of  the  American  Medical  Association,  Sept. 
Record, Sept.  l">,  IS  :  l,  1883. 

Also  for  sale  separate — 

HOLDEN,  LUTHER,  F.  R.  C.  8., 

"nd  the  Foundling  Hospitals,  London. 

Landmarks,  Medical  and  Surgical.  Second  American  from  the  latest  revised 
English  edition,  with  additions  by  W.  \\\  Keen,  M.  P.,  Professor  of  Artistic  Anatomy  in 
the  Pennsylvania  Academy  of  l lie  Fine  Arts,  formerly  Lecturer  on  Anatomy  in  the  Phila- 
delphia School  of  Anatomy.      In  one  handsome  12mo.  volume  of  148  pages.     (  loth,  $1.00. 

This  little  book  is  all  that  can  be  desired  within  almost  to  learn  it  by  heart,    [t  teaches  diagnosis  by 

intents  will  he  found  simply  in-  external  examination,  ocular  and  palpable,  of  the 

valuable  to  the  young  surgeon  or  physician,  since  body,  with  such  anatomical  and  physiological  facts 

they  bring  before  him  Buch  data  a-  he  requiresat  as  directly  bear  on  the  subject    ft  is  eminently 

every  examination  of  a  patient.     It  is  written  in  the  student's  and  young  practitioner's  book.— Phy- 

language  so  clear  and  concise    that   one    ought  -  Nov.  1881. 


WILSON,  ERASMUS,  F.  R.  8. 

A  System  of  Human  Anatomy,  General  and  Special.  Edited  by  W.  H. 
G(  bki  cht,  M.  I  >.,  Professor  of  General  and  Surgical  Anatomy  iii  the  Medical  College  of 
Ohio.  In  one  large  and  handsome  octavo  volume  of  61(5  pages,  with  oi'7  illustrations. 
Cloth.  $4.00;    leather,  $5.00. 

SMITH,  II.  II,  M.  />.,  and   HORNER,  WM.  E..M.I)., 

Prof,  of  Surgery  in  the  Univ.  of  Penna.,  etc.        Latt  Prof,  of  AnaU  in  the  Univ.  of  Penna. 

An  Anatomical  Atlas,  Illustrative  of  the  Structure  of  the  Human  Body.  In  one 
large  imperial  octavo  volum>,  of  200  pages,  with  <io4  beautiful  figures.      Cloth,  $4.50. 

CLELAXD.  JOHN,  M.  />.,  F.  R.  S., 

Prof essor  of  Anatomy  and  Ph 

A  Directory  for  the  Dissection  of  the  Human  Body.  In  one  12mo. 
volume  of  178  pages.     (  loth,  $1.25. 


6  Lea  Brothers  &  Co.'s  Publications — Anatomy. 

ALLIEN,  HARRISON,  31.  !>., 

Professor  ol  Physiology  in  the  University  of  Pennsylvania. 

A  System  of  Human  Anatomy,  Including  Its  Medical  and  Surgical 
Relations.  For  the  use  of  Practitioners  and  Students  of  Medicine.  With  an  Intro- 
ductory Section  on  Histology.  By  E.  O.  Shakespeare,  M.  D.,  Ophthalmologist  to 
the  Philadelphia  Hospital.  Comprising  813  double-columned  quarto  pages,  with  380 
illustrations  on  109  full  page  lithographic  plates,  many  of  which  are  in  colors,  and  241 
engravings  in  the  text.  In  six  Sections,  each  in  a  portfolio.  Section  I.  Histology. 
Section  II.  Bones  and  Joints.  Section  III.  Muscles  and  Fasces:.  Section  IV. 
Arteries,  Veins  and  Lymphatics.  Section  V.  Nervous  System.  Section  VI. 
Organs  of  Sense,  of  Digestion  and  Genito-Urinary  Organs,  Embryology, 
Development,  Teratology,  Superficial  Anatomy,  Post-Mortem  Examinations, 
and  General  and  Clinical  Indexes.  Price  per  Section,  each  in  a  handsome  portfolio, 
$3.50 ;  also  bound  in  one  volume,  cloth  $23.00 ;  very  handsome  half  Russia,  raised  bands 
and  open  back,  $25.00.     For  sale  by  subscription  only.     Apply  to  the  Publishers. 

Extract   from   Introduction. 

It  is  the  design  of  this  book  to  present  the  facts  of  human  anatomy  in  the  manner  best 
suited  to  the  requirements  of  the  student  and  the  practitioner  of  medicine.  The  author 
believes  that  such  a  book  is  needed,  inasmuch  as  no  treatise,  as  far  as  he  knows,  contains,  in 
addition  to  the  text  descriptive  of  the  subject,  a  systematic  presentation  of  such  anatomical 
facts  as  can  be  applied  to  practice. 

A  book  which  will  be  at  once  accurate  in  statement  and  concise  in  terms  ;  which  will  be 
an  acceptable  expression  of  the  present  state  of  the  science  of  anatomy ;  which  will  exclude 
nothing  that  can  be  made  applicable  to  the  medical  art,  and  which  will  thus  embrace  all 
of  surgical  importance,  while  omitting  nothing  of  value  to  clinical  medicine, — would  appear 
to  have  an  excuse  for  existence  in  a  country  -where  most  surgeons  are  general  practitioners, 
and  where  there  are  few  general  practitioners  who  have  no  interest  in  surgery. 

It  is  to  be  considered  a  study  of  applied  anatomy  '  care,  and  are  simply  superb.  There  is  as  much 
in  its  widest  sense — a  systematic  presentation  of  ;  of  practical  application  of  anatomical  points  to 
such  anatomical  facts  as  can  be  applied  to  the  j  the  every-day  wants  of  the  medical  clinician  as 
practice  of  medicine  as  well  as  of  surgery.  Our  to  those  of  the  operating  surgeon.  In  fact,  few 
author  is  concise,  accurate  and  practical  in  his  general  practitioners  will  read  the  work  without  a 
statements,  and  succeeds  admirably  in  infusing  feeling  of  surprised  gratification  that  so  many 
an  interest  into  the  study  of  what  is  generally  con-  points,  concerning  which  they  may  never  have 
sidered  a  dry  subject.  The  department  of  Histol-  thought  before  are  so  well  presented  for  their  con- 
ogy  is  treated  in  a  masterly  manner,  and  the  sideration.  It  is  a  work  which  is  destined  to  be 
ground  is  travelled  over  by  one  thoroughly  famil-  the  best  of  its  kind  in  any  language. — Medical 
far  with  it.    The  illustrations  are  made  with  great    Record,  Nov.  25, 1882. 


CLARKE,  W.  B.,  F.R.  C.S.  &  LOCKWOOD, C.  B.,  F.R.  C.S. 

Demonstrators  of  Anatomy  at  St.  Bartholomew's  Hospital  Medical  School,  London. 
The  Dissector's  Manual.     In  one  pocket-size  12mo.  volume  of  396  pages,  with 
49   illustrations.     Limp   cloth,   red  edges,   $1.50.      Just  ready.     See  Students'  Seiies  of 
Manuals,  page  3. 

This  is  a  very  excellent  manual  for  the  use  of  the    part,  are  good  and  instructive.    The  book  is  neat 
student  who  desires  to  learn  anatomy.   The  meth-  .  and  convenient.    We  are  glad  to  recommend  it.— 
ods  of  demonstration  seem  to  us  very  satisfactory.  :  Boston  Medical  and  Surgical  Journal,  Jan.  17, 1884. 
There  are  many  woodcuts  which,  for  the  most 


TREVES,  ERELJERLCK,  F.  R.  C.  S., 

Senior  Demonstrator  of  Anatomy  and  Assistant  Surgeon  at  the  London  Hospital. 
Surgical  Applied  Anatomy.     In  one  pocket-size  12mo.  volume  of  540  pages, 
with  61  illustrations.   Limp  cloth,  red  edges,  $2.00.     Just  ready.     See  Students'  Series  of 
Manuals,  page  3. 

He  has  produced  a  work  which  will  command  a  I  quickened  by  daily  use  as  a  teacher  and  practi- 
larger  circle  of  readers  than  the  class  for  which  it  tioner,  has  enabled  our  author  to  prepare  a  work 
was  written.  This  union  of  a  thorough,  practical  which  it  would  be  a  most  difficult  task  to  excel. — 
acquaintance  with  these  fundamental  branches,  I  The  American  Practitioner  Feb.  1884. 

curnow,  john, Yld.,  f. r7of., 

Professor  of  Anatomy  at  King's  College,  Physician  at  King's  College  Hospital. 
Medical  Applied  Anatomy.     In  one  pocket-size   12mo.  volume.    Preparing-. 
See  Students'  Series  of  Manuals,  page  3. 

BELLA3IY,  EDWARD,  F.  R.  C.  S., 

Senior  Assistant-Surgeon  to  the  Charing-Cross  Hospital,  London. 

The  Student's  Guide  to  Surgical  Anatomy :  Being  a  Description  of  the 
most  Important  Surgical  Eegions  of  the  Human  Body,  and  intended  as  an  Introduction  to 
operative  Surgery.    In  one  12mo.  volume  of  300  pages,  with  50  illustrations.    Cloth,  $2.25. 

HARTSHORNE'S    HANDBOOK    OF   ANATOMY  HORNER'S  SPECIAL  ANATOMY  AND  HISTOL- 

AND  PHYSIOLOGY.    Second  edition,  revised.  |      OGY.    Eighth  edition,  extensively  revised  and 

In  one  royal  12mo.  volume  of  310  pages,  with  220  i      modified.    In  two  octavo  volumes  of  1007  pages, 

woodcuts.     Cloth,  $1.75.  with  320  woodcuts.     Cloth,  $6.00. 


Lea  Brothers  &  Co.'s  Publications — Physics,  Physiol.,  Anat.         7 
DRAPER,  JOHN  C  M.  JO.,  LL.  !>., 

Professor  of  Chemistry  in  the  University  of  the  City  of  New  York. 

Medical  Physics.  A  Text-book  for  Students  and  Practitioners  of  Medicine.  In 
one  octavo  volume  of  734  pages,  with  376  woodcuts,  mostly  original.    Cloth,  $4.    Just  ready  . 

From  the  Preface. 

The  fact  that  a  knowledge  of  Physics  is  indispensable  to  a  thorough  understanding  of 
Medicine  has  not  been  as  fully  "realized  in  this  country  aa  in  Europe,  where  the  admirable 
works  of  Desplats  and  Gariel,  of  Robertson  and  of  numerous  German  writers  constitute  a 
branch  of  educational  literature  to  which  we  can  show  no  parallel.  A  full  appreciation 
of  this  the  author  trusts  will  be  sufficient  justification  for  placing  in  book  form  the  sub- 
stance of  his  lectures  on  this  department  of  science,  delivered  during  many  years  at  the 
University  of  the  City  of  New  York. 

Broadly  speaking,  this  work  aims  to  impart  a  knowledge  of  the  relations  existing 
between  Physics  and  Medicine  in  their  latest  state  of  development,  and  to  embody  in  the 
pursuit  of  this  object  whatever  experience  the  author  has  gained  during  a  long  period  of 
teaching  this  special  branch  of  applied  science. 

Certainly  we  have  no  text-book  as  full  as  the  ex-  and   it  is  one    of  the    most   valuable    scientific 

cellent  one  he  has  prepared.    It  begins  with   a  trc                   en   to  the  medical  profession  for  a 

statement  of  the  properties  of  matter  and  energy,  number  of  years.    It  is  profusely  and  handsomely 

After  these  the  special  departments  of  physics  are  illustrated.    The  work  should  have  a  place  upon 

explained,  acoustics,  optics,  heat,  electricity  and  every  physician's  library  shelf. — Maryland  M 

magnetism,    closing   with    a  section  on  electro-  Journal,. Jn\v  IS,  1885.    q. 

biology.  The  applications  of  all  these  to  physiology  This  is  the  only  work  with  which  we  are  ac- 
and  medicine  are  kept  constantly  in  view.  The  quainted  in  which  physics  is  treated  with  reference 
text  is  amply  illustrated  and  the  many  difficult  to  medicine.  Preceptors  who  are  axious  that  their 
points  of  the  subject  are  brought  forward  with  re-  pupils  should  have  a  scientific  knowledge  of  med- 
markable  clearness  and  ability. — Medical  and  Surg-  iciue,  should  make  this  work  a  textbook,  and  re- 
order, July  18, 1885.    q.  quire  a  thorough  study  of  it. — C                   Jdical 

The  volume  from  beginning  to  end  teems  with  News,  July  18,  1885.    q." 
useful  information.    Take  the  book  as  a  whole 


robertsow,  j.  McGregor,  m.  a.,  m.  b., 

ead  Demonstrator  of  Physiology,  University  of  Glasgow. 
Physiological  Physics.     In  one  12mo.  volume  of  537  pages,  with  219  illustra- 
tions.    Limp  cloth,  $2.00.     Just  ready.     See  Students'  Series  of  Manuals,  page  3. 

The  title  of  this  work  sufficiently  explains  the  ments.  It  will  be  found  of  great  value  to  the 
nature  of  its  contents.  It  is  designed  as  a  man-  practitioner.  It  is  a  carefully  prepared  book  of 
ual  for  the  student  of  medicine,  an  auxiliary  to  reference,  concise  and  accurate,  and  as  such  we 
his  text-book  in  physiology,  and  it  would  be  particu-  heartily  recommend  it.— Journal  of  the  American 
larly  useful   as  a  guide  to  his  laboratory  experi-    Medical  Association,  Dec  6, 1884. 

DALTON,  JOHN  a,  M.  D., 

Professor  Emeritus  of  Physiology  in  the  College  of  Physicians  and  Surgeons,  New  York. 

Doctrines  of  the  Circulation  of  the  Blood.     A  History  of  Physiological 
Opinion  a::  ry  in  regard  to  the  Circulation  of  the  Blood.      In   one  handsome 

12mo.  volume  of  293  pages.     Cloth,  $2.     Just  ready. 

Dr.  Dalton's  work  is  the  fruit  of  the  deep  research  revolutionized  the  theories  of  teachers,  than  the 
of  a  cultured  mind,  and  to  the  busy  practitioner  it  discovery  of  the  circulation  of  the  Hood.  This 
cannot  fail  to  be  a  source  of  instruction.    It  will    explains'  the  extraordinary  ini  -  to  all 

inspire  him  with  a  feeling  of  gratitute  and  admir-  medical  historians.  The  volume  before  us  is  one 
ation  for  those  plodding  workers  of  olden  times,  of  three  or  four  which  have  been  written  within  a 
who  laid  the  foundation  of  the  magnificent  temple  few  years  by  American  physicians.  It  is  in  several 
of  medical  scienci  te.   The  volume,  though 

small  in  size,  is  one  of  the  most  creditable  con- 
In  the  progress  of  physiological  study  no  fact    tribntions  from  an  American  pen  to  medical  1, 

f   greater  moment,  none  more  completely    that  has  appeared. — Med.  &  Surg.  Rep.,  Dec.  6, 1884. 

BY   THE    SAME   AUTHOR. 
The  Topographical  Anatomy  of  the  Brain.   In  three  very  handsome  quarto 
volumes  comprising  178  pages  of  descriptive  text.     Illustrated  with  48  full  page  photo- 
graphic plates  of  Brain  Sections,  with  a  like  number  of  explanatory  plates,  as  well  as  many 
woodcuts  through  the  text. 


BELL,  F.  JEFFREY,  M.  A., 

Professor  of  Comparative  Anatomy  at  King's  College,  London. 

Comparative  Physiology  and  Anatomy.  In  one  12mo.  volume  of  561  pages, 
with 229 illustrations.  Limpcloth, $2.00.  Justready.  See S>  «ls,  page3. 

ELLIS,  GEORGE  VINJEM, 

Emeritus  Professor  of  Anatomy  in   University  College,  London. 

Demonstrations    of  Anatomy.      Being  a  Guide  to  the   Knowledge  of  the 
Human  Body  by  Dissection.     From  the  eighth  and  i  idon  edition.     In  one  very 

handsome  octavo  volume  of  716  pages,  with  249  illustrations.    Cloth,  $4.25;  leather,  | 

ROBERTS,  JOHX  Ji..  A.  M.,  M.  />., 

Prof,  of  Applied  Anat.  and  Oper.  Surg,  in  Phila.  Polyclinic  and  Coll.  for  Graduates  in  Medicine. 
The  Compend  of  Anatomy.     For  use  in  the  dissecting-room  and  in  preparing 
for  examinations.     In  one  16mo.  volume  of  19G  pages.     Limp  cloth,  75  cents. 


8        Lea   Brothers  &  Co.'s  Publications — Physiology,  Chemistry. 


DALTOX,  JOIIN  C,  31.  D., 

I  ■    rieions  and  Surgeons,  Neio  York,  etc. 
A  Treatise   Oil   Human  Physiology.      Designed  for  the  use  of  Students  and 
Practitioners   of  Medicine.     Seventh  edition,  thoroughly  revised  and  rewritten.     In  one 
very  handsome  octavo  volume  of  722  pages,  with  252  beautiful  engravings  on  wood.    Cloth, 
f>5.00;  leather,  $6.00;  very  handsome  half  Russia,  raised  hands,  $6.50. 

The  merits  of  Professor  Dalton's  text-book.  his  more  compact  form,  yet  its  delightful  charm  is  re- 
smooth  and  pleasing  style,  the  remarkable  clear-  tained,  and  no  subject  is  thrown  into  obscurity. 
DOSS  of  his  descriptions,  which  leave  not  a  chapter  l  Altogether  this  edition  is  far  in  advance  of  any 
obscure,  his  cautions  judgment  and  the  general  previous  one,  and  will  tend  to  keep  the  profession 
correctness  of  his  facts,  are  perfectly  known.  They  posted  as  to  the  most  recent  additions  to  our 
have  made  his  text-book  the  one  most  familiar  physiological  knowledge. — Michigan  Medical  News, 
to  American  students. — Med,  Record,  Match  4,  1882.    April,  1882. 

Certainly  no  physiological  work  has  ever  issued  j  One  can  scarcely  open  a  college  catalogue  that 
from  the  press  that  presented  its  subject-matter  in  does  not  have  mention  of  Dalton's  Physiology  as 
a  clearer  and  more  attractive  light.  Almost  every  the  recommended  text  or  consultation-book.  For 
page  bears  evidence  of  the  exhaustive  revision  American  students  we  would  unreservedly  recom- 
that  has  taken  place.    The  material  is  placed  in  a    mend  1  »r.  Dalton's  woTlt.-Va.  Med.  Monthly,  July, *82. 

FOSTER,  3IICHAEL,  M.  JD.,  JF.  bVs., 

Prelector  in  Physiology  and  Fellow  of  Trinity  College,  Cambridge,  England. 
Text-Book  of  Physiology.     Third  American  from  the  fourth  English  edition, 
with  notes  and  additions  by  E.  T.  Reichert,  M.  D.     In  one  handsome  royal  12mo.  volume 
of  908  pages,  with  271  illustrations.  Cloth.  $3.25;  leather,  $3.75.   Just  ready. 

Dr.  Foster's  work  upon  physiology  is  so  well-  to  know  and  what  may  be  passed  over  by  them  as 
known  as  a  text-book  in  this  country,  that  it  needs    not  important.    From  the  beginning  to  the  end, 

physiology  is  taught  in  a  systematic  manner.  To 
this  third  American  edition  numerous  additions, 
corrections  and  alterations  have  been  made,  so 
that  in  its  present  form  the  usefulness  of  the  book 
will  l>e  found  to  be  much  increased. —  Cincinnati 
Mtdical  News,  July  1885. 


but  little  to  be  said  in  regard  to  it.  There  is 
scarcely  a  medical  college  in  the  United  States 
where  it  is  not  in  the  hands  of  the  students.  '1  hp 
author,  more  than  any  other  writer  with  whom 
we  are  acquainted,  seems  to  understand  what 
portions  of  the  science  are  essential  for  students 


POWER,  HEXRY,  31.  B.,  F.  R.  C.  S., 

Examiner  in  Physiology,  Royal  College  of  Surgeons  of  England. 
Human  Physiology.      In  one  handsome  pocket-size  12mo.  volume  of  396  pages, 
with  47  illustrations.     Cloth,  $1.50.     See  Students'  Series  of  Manuals,  page  3. 


The  prominent  character  of  this  work  is  that  of 
judicious  condensation,  in  which  an  able  and  suc- 
cessful effort  appears  to  have  been  made  by  its 
accomplished  author  to  teach  the  greatest  number 
of  facts  in  the  fewest  possible  words.  The  result 
is  a  specimen  of  concentrated  intellectual  pabu- 
lum seldom  surpassed,  which  ought  to  be  care- 
fully ingested  and  digested  by  every  practitioner 
who  desires  to  keep  himself  well  informed  upon 
this  most  progressive  of  the  medical  sciences. 
The  volume  is  one  which  we  cordiallv  recommend 


to  every  one  of  our  readers. — The  American  Jour- 
nal of  the  Medical  8cit  nees,  October,  1884. 

This  little  work  is  deserving  of  the  highest 
praise,  and  we  can  hardly  conceive  how  the  main 
facts  of  this  science  could  have  been  more  clearly 
or  concisely  stated.  The  price  of  the  work  is  such 
as  to  place  it  within  the  reach  of  all,  while  the  ex- 
cellence of  its  text  will  certainly  secure  for  it  most 
favorable  c  mmendation — Cincinnati  Lancet  and 
Clinic,  Feb.  16,  1884. 


CARPENTER,  W3L  B.,  31.  D.,  F.  R.  S.,  F.  G.  S.,  F.  L.  S., 

Registrar  to  the  University  of  London,  etc. 

Principles  of  Human  Physiology.  Edited  by  Henry  Tower,  M.  B.,  Lond., 
F.  R.  C.  S.,  Examiner  in  Natural  Sciences,  University  of  Oxford.  A  new  American  from  the 
eighth  revised  and  enlarged  edition,  with  notes  and  additions  by  Francis  G.  Smith,  M.  D., 
late  Professor  of  the  Institutes  of  Medicine  in  the  University  of  Pennsylvania.  In  one 
very  large  and  handsome  octavo  volume  of  1083  pages,  with  two  plates  and  373  illus- 
trations.   Cloth,  $5.50;  leather,  $6.50;  half  Russia,  $7. 

FOTVXES,  GEORGE,  Ph.  I). 

A  Manual  of  Elementary  Chemistry;  Theoretical  and  Practical.  Em- 
bodying "Watts'  Inorganic  Chemistry.  New  American  edition.  In  one  large  royal  12mo. 
volume  of  over  1000  pages,  with  200  illustrations  on  wood  and  a  colored  plate.  Cloth, 
$2.75;   leather,  $3.25.     In  a  few  days. 

A  notice  of  the  previous  edition  is  appended. 


The  book  opens  with  a  treatise  on  Chemical 
Physics,  including  Heat,  Light,  Magnetism  and 
Electricity.  These  subjects  are  treated  clearly 
and  briefly,  hut  enough  is  given  to  enable  the  stu- 
dent to  comprehend  the  facts  and  laws  of  Chemis- 
try proper.  It  is  the  fashion  of  late  years  to  omit 
these  topics  from  works  on  chemistry  but  their 
omission  is  not  to  be  commended.  As  was  required 
by  the  great  advance  in  the  science  of  Chemistry 


of  late  years,  the  chapter  on  the  General  Principles: 
of  Chemical  Philosophy  has  been  entirely  rewrit- 
ten. The  latest  views  on  Equivalents,  Quantiva- 
lence,  etc.,  are  clearly  and  fully  set  forth.  This 
last  edition  is  a  great  improvi  ment  upon  its  prede- 
cessors, which  is  saying  not  a  little  of  a  book  that 
has  reached  its  twelfth  edition. — Ohio  Medical  Re- 
corder, Oct.,  1878. 


"Wohler's  Outlines  of  Organic  Chemistry.     Edited  by  Fittig.    Translated 
by  Ira  Remsen,  M.  D.,  Ph.  D.     In  one  12mo.  volume  of  550  pages.     Cloth,  $3. 

GALLOWAY'S  QUALITATIVE  ANALYSIS.    New  i  CARPENTER'S  PRIZE  ESSAY  ONTHEUSE  AND 
edition.  Abuse  OF  Aloobolic  Liquors  in  Health  and  Dis- 

LEHM  ANN'S  MANUAL  OF  CHEMICAL  PHYS-        bass.  With  explanations  of  scientific  words.  Small 
IOLOGY.     In  one  octavo  volume  of  327  pages,        12mo.    178  pages.    Cloth,  GO  cents, 
with  41  illustrations.    Cloth, $2.25. 


Lea  Brothers  &  Co.'s  Publications — Chemistry. 


FRAXKEAXB,E.,Z>.  C. L.,F.R.S.,&JAPP,  F.R.,F.E  C, 


Professor  of  Chemistry  in  the  Xormal  School 
of  Science,  London. 


Assist.  Prof,  of  Ch<  mistry  in  the  Xormal 
School  of  ■•  ion. 


Inorganic  Chemistry.    In  one  handsome  octavo  volume  of  GOO  pages,  with  51 
woodcuts  and  2  lithographic  plates.     Cloth,  $3.75;  Leather,  $4.75.     la  a  few  days. 

This  work  on  elementary  chemistry  is  based  upon  principles  of  classification,  nomen- 
clature and  notation  which  have  been  proved  by  nearly  twenty  years  experience  in  teaching 
to  impart  most  readily  a  sound  and  accurate  knowledge  of  the  science. 

ATTFIELI>9  JOHX,  Ph.  D.. 

Profa  '  'V  t'i  the  Pharmaceutical  Society  of  Great  Britain,  etc. 

Chemistry,  General,  Medical  and  Pharmaceutical;  Including  the  Chem- 
istry of  the  U.  S.  Pharmacopoeia.  A  .Manual  of  the  General  Principles  of  the  Science, 
and  their  Application  to  Medicine  and  Pharmacy.  A  new  American,  from  the  tenth 
English  edition,  specially  revised  by  the  Author.  In  one  handsome  royal  12mo.  volume 
of  7-_!>  pages,  with  87  illustrations.  Cloth,  §2.50;  leather,  $3.00. 
A  text-book  which  passes  through  ten  editions    to  put  himself  in  the  student's  place  and  to  appre 


in  sixteen  years  must  have  good  qualities.  This 
remark  is  certainly  applicable  to  Attfiehl's  Chem- 
istry, a  b  wk  which  IS  so  well  known  that  it  is 
hardly  necessary  to  do  more  than  note  the  appear- 
ance of  this  new  and  improved  edition,  li  - 
however,  desirable  to  point  out  that  feature  of  the 
book  which,  in  all  probability,  his  made  it  so 
popular.  There  can  be  little  doubt  that  it  is  its 
thoroughly  practical  character,  the  expi 
being  used  in  its  best  sense.  The  author  under- 
stand.-, what  the  student  ought  to  learn,  and  is  able 


ciate  his  state  of  mind.— 'American  Chemical  Jour- 
not,  April,  1884. 
It  is  a  book  on  which  too  much  praise  cannot  be 
I.     As  a  textbook   for  medical  schools  it 
is  unsurpassable  in  the  present  state  of  chemical 
science,  and  having  been  prepared  with  a  special 
view  towards  medicine  and  pharmacy,  it  is  alike 
nsable  to  all  persons  engaged  in  those  de- 
partments   of  science.      It    includes    the    whole 
chemistry  of  the  last  Pharmacopoeia.— Pacific  Medt- 
cal  and  Sugrical  Journal,  Jan.  lssl. 


BLOXAM,  CHARLES  E., 

Professor  of  Chemistry  in  King's  College,  London. 

Chemistry,  Inorganic  and  Organic.  New  American  from  the  fifth  Lon- 
don edition,  thoroughly  revised  and  much  improved.  In  one  very  handsome  octavo 
volume  of  727  pages,  with  292  illustrations.     Cloth,  $3.75;  leather,  $4.75. 


Comment  from  us  on  this  standard  work  is  al- 
most superfluous.     It  differs  widely  in  scope  and 
aim  from  that  of  Att  field,  and  in  its  way  is  equally 
beyond  criticism.    It  adopts  the  most  direct  meth- 
ods in  stating  the  principles,  hypotheses  ami  (acts 
of  the  science,     Its  language  is  so  terse  and  lucid, 
and  its  arrangement  of  matter  so  logical  in  se-  : 
that  the  student  never  has  occasion  to 
complain  that  chemistry  is  a  hard  study.    Much  I 
attention  is  paid  to  experimental  illustrations  of  i 
chemical     principles    and    phenomena,    and   the 
>f  conducting  these  experiments.    Thebookj 
maintains  the  position  it  has  always  held  as  one  of  | 


the  best  manuals  of  general  chemistry  in  the  Eng- 
lish language. — Detroit  Lancet,  Feb.  1884. 

The  general  plan  of  this  work  remains  the 
same  as  in  previous  editions,  the  evident  object 
being  to  give  clear  and  concise  descriptions  of  all 
known  elements  and  of  their  most  important 
compounds,  with  explanations  of  the  chemical 
laws  and  principles  involved.  We  gladly  repeat 
now  the  ©pinion  we  expressed  about  a  former 
edition,  that  we  regard  Bloxam's  Chemistry  as 
one  oi  the  best  treatises  on  general  and  applied 
chemistry. — American  Jour,  of  Pharmacy,  Dec.  1883. 


SIMON,  W.,  Ph.  J).,  M.  Z>., 

Professor  of  Chemistry  and  Toxicology  m  the  College  of  Physicians  and  Surgeons,  Baltimore,  and 
Professor  of  Chemistry  in  the  Maryland  College,  of  Pharmacy. 
Manual  of  Chemistry.  A  Guide  to  Lectures  and  Laboratory  work  for  Beginners 
in  Chemistry.  A  Text-book,  specially  adapted  for  Students  of  Pharmacy  and  Medicine. 
In  one  8vo.  vol.  of  410  pp.,  with  16  woodcuts  and  7  plates,  mostly  of  actual  deposits, 
with  colors  illustrating  56  of  the  most  important  chemical  reactions.  Cloth,  $3.00;  also 
without   plates,    cloth,  $2.50.     Just  ready. 

plates,  beautifully  executed,  illustrating  precipi- 
tates  of  various  reactions,  form  a  novel  and  valu- 


This  book  supplies  a  want  long  felt  by  students 
of  medicine  and  pharmacy,  ana  is  a  concise  but 

thorough  treatise  on  the  subject.     The  long  expe- 
rt the  author  as  a  teacher  in  schools  of 
medicine  and   pharmacy  is  conspicuous   in  tie' 

perfect  adaptation  of  the  work  to  the  special  n Is 

of  the  student  of  these  branches.     The  i 


able  feature  of  the  book,  and  cannot  fail  to  be  ap- 
preciated by  both  student  and  teacher  as  a  help 
over  the  hard  places  of  the  science. — Maryland 
Medical  Journal,  Nov.  22,  1884. 


REJISEX.  IRA,  M.  I).,  Ph.  T>., 

Professor  of  Chemistry  in  the  Johns  Hopkins  Unirersiti/,  Baltimore. 
Principles  of  Theoretical  Chemistry,  with  special  reference  to  the  Constitu- 
tion of  Chemical  Compounds.    Second  and  revised  edition.    In  one  handsome  royal  12mo. 
volume  oi  240  pages.     Cloth,  $1.75.    Just  ready. 

of  chemistry.  The  high  reputation  of  the  author 
assures  its  accuracy  in  all  matters  of  fact,  and  its 
judicious  conservatism  in  matters  of  theory,  com- 
bined with  the  fulness  with  which,  in  a  small 
--,  the  present  attitude  of  chemical  science 
towards  the  constitution  of  compounds  is  con- 
sidered, give-  it  a  value  much  beyond  that  accorded 
to  the  average  text-books  of  the  day. — American 
Journal  of  Science,  March,  1884. 


The  book  is  a  valuable  contribution  to  the  chemi- 
cal literature  of  instruction.    That  in  so  few  years 

a  second  edition  ha-  I □  called  for  indicates  that 

many  chemical  teacher-  have  been  found  ready 
to  endorse  its  plan  and  to  adopt  it-  methods.     In 
this  edition  a  considerable  proportion  of  the  book 
has  I. ecu  rewritten,  much   new  matter   hae 
added  and  the  wholi  brought  up  to  date. 

We  earnestly  commend  this  book  to  every  student 


10 


Lea  Brothers  &  Co.'s  Publications — Chemistry. 


CHARLES,  T.  CRANSTOUN,  M.  JD.,  F.  C.  S.,  M.  S., 

Fbrmeriy  At  Demonst.  of  Chemistry  and  Chemical  Physics,  Queen's  College,  Belfast. 

The  Elements  of  Physiological  and  Pathological  Chemistry.  A 
Handbook  for  Medical  Students  and  Practitioners.  Containing  a  general  account  of 
Nutrition,  Foods  ami  Digestion,  and  the  Chemistry  of  the  Tissues,  Organs,  Secretions  and 
Excretions  of  the  Body  in  Health  and  in  Disease.  Together  with  the  methods  for  pre- 
paring or  separating  their  chief  constituents,  as  also  for  their  examination  in  detail,  and 
an  outline  syllabus  of  a  practical  course  of  instruction  for  students.  In  one  handsome  octavo 
volume  of  463  pages,  with  38  woodcuts  and  1  colored  plate.     Cloth,  $3.50. 


The  work  is  thoroughly  trustworthy,  and  in- 
formed throughout  by  a  genuine  scientific  spirit. 
The  author  deals  with  the  chemistry  of  the  diges- 
tive secretions  in  a  systematic  manner,  which 
leaves  nothing  to  be  desired,  and  in  reality  sup- 
plies a  want  in  English  literature.  The  book  ap- 
pears to  us  to  he  at  once  full  and  systematic,  and 
to  show  a  just  appreciation  of  the  relative  import- 
ance of  the  various  subjects  dealt  with. — British 
Medical  Journal,  November  29,  ISS-i. 


Dr.  Charles' manual  admirably  fulfils  its  inten- 
tion of  giving  his  readers  on  the  one  hand  a  sum- 
mary, comprehensive  but  remarkably  compact,  of 
the  mass  of  facts  in  the  sciences  which  have  be- 
come indispensable  to  the  physician;  and,  on  the 
other  hand,  of  a  system  of  practical  directions  so 
minute  that  analyses  often  considered  formidable 
may  be  pursued  by  any  intelligent  person. — 
,  Dee.  1884. 


HOFFMANN,  F.,  A.M.,  Fh.H.,   &  FOWER  F.B.,  Fh.I)., 

Public  Analyst  to  the  State  of  yew  York.  Prof,  of  Anal.  Chem.  in  the  Phil.  Coll.  of  Pharmacy. 

A  Manual  of  Chemical  Analysis,  as  applied  to  the  Examination  of  Medicinal 
Chemicals  and  their  Preparations.  Being  a  Guide  for  the  Determination  of  their  Identity 
and  Quality,  and  for  the  Detection  of  Impurities  and  Adulterations.  For  the  use  of 
Pharmacists,  Physicians,  Druggists  and  Manufacturing  Chemists,  and  Pharmaceutical  and 
Medical  Students.  Third  edition,  entirely  rewritten  and  much  enlarged.  In  one  very 
handsome  octavo  volume  of  621  pages,  with  179  illustrations.    Cloth,  $4.25. 

We  congratulate  the  author  on  the  appearance 
of  the  third  edition  of  this  work,  published  for  the 
first  time  in  this  country  also.  It  is  admirable  and 
the  information  it  undertakes  to  supply  is  both 
extensive  and  trustworthy.  The  selection  of  pro- 
cesses for  determining  the  purity  of  the  substan- 
ces of  which  it  treats  is  excellent  and  the  descrip- 


tion of  them  singularly  explicit.  Moreover,  it  is 
exceptionally  free  from  typographical  errors.  We 
have  no  hesitation  in  recommending  it  to  those 
who  are  engaged  either  in  the  manufacture  or  the 
testing  of  medicinal  chemicals. — London  Pharma- 
ceutical Journal  and  Transactions,  1883. 


CLOWES,  FRANK,  L>.  Sc,  London, 

Senior  Science-Master  at  the  High  School,  Newcastle-under-Lyme,  etc. 

An  Elementary  Treatise  on  Practical  Chemistry  and  Qualitative 
Inorganic  Analysis.  Specially  adapted  for  use  in  the  Laboratories  of  Schools  and 
Colleges  and  by  Beginners.  Third  American  from  the  fourth  and  revised  English  edition. 
In  one  very  handsome  royal  12mo.  volume  of  about  400  pages,  with  about  50  illustrations. 
Cloth,  $2.50.     In  a  few  days. 


The  style  is  clear,  the  language  terse  and  vigor- 
ous. Beginning  with  a  list  of  apparatus  necessary 
for  chemical  work,  he  gradually  unfolds  the  sub- 
ject from  its  simpler  to  its  more  complex  divisions. 
It  is  the  most  readable  book  of  the  kind  we  have 
yet  seen,  and  is  without  doubt  a  systematic, 
intelligible  and  fully  equipped  laboratory  guide 


and  text  book. — Medical  Record,  July  18,  1885. 

We  may  simply  repeat  the  favorable  opinion 
which  we  expressed  after  the  examination  of  the 
previous  edition  of  this  work.  It  is  practical  in  its 
aims,  and  accurate  and  concise  in  its  statements. 
— American  Journal  of  Pharmacy,  August,  1885. 


RALFE,  CHARLES  H.,  M.  D.,  F.  R.  C.  F., 

Assistant  Physician  at  the  London  Hospital. 
Clinical  Chemistry.     In  one  pocket-size  12mo.  volume  of  314  pages,  with  16 


illustrations.  Limp  cloth,  red  edges,  $1.50. 
This  is  one  of  the  most  instructive  little  works 
that  we  have  met  with  in  a  long  time.  The  author 
is  a  physician  and  physiologist,  as  well  as  a  chem- 
iat,  consequently  the  book  is  unqualifiedly  prac- 
tical, telling  the  physician  just  what  he  ought  to 
know,  of  the  applications  of  chemistry  in  medi- 


See  Students'  Series  of  Manuals,  page  3. 
cine.  Dr.  Ralfe  is  thoroughly  acquainted  with  the 
iatest  contributions  to  his  science,  and  it  is  quite 
refreshing  to  find  the  subject  dealt  with  so  clearly 
and  simply,  yet  in  such  evident  harmony  with  the 
modern  scientific  methods  and  spirit. — Medical 
Record,  February  2, 18S4. 


CLASSEN,  ALEXANDER, 

Professor  in  the  Royal  Polytechnic  Sellout,  Aix-la-Cliapelle. 

Elementary  Quantitative  Analysis.  Translated,  with  notes  and  additions,  by 
Edgar  F.Smith.  Ph.D.,  Assistant  Professor  of  Chemistry  in  the  Towne  Scientific  School, 
University  of  Penna.     In  one  12mo.  volume  of  324  pages,  with  36  illust.     Cloth,  $2.00. 


It  is  probably  the  best  manual  of  an  elementary 

nature  extant    insomuch  as  its  methods  are  the 

It  teaches  by  examples,  commencing  with 

single   determinations,    followed  by  separations, 


and  then  advancing  to  the  analysis  of  minerals  and 
such  products  as  are  met  with  in  applied  chemis- 
try. It  is  an  indispensable  book  tor  students  in 
chemistry. — Boston  Journal  of  Chemistry,  Oct.  1878. 


GREENE,  WILLIAM  H.,  M.  H., 

Demonstrator  of  Chemistry  in  the  Medical  Department  of  the  University  of  Pennsylvania. 
A  Manual  of  Medical  Chemistry.  For  the  use  of  Students.  Based  upon  Bow- 
man's Medical  Chemistry.  In  one  12mo.  volume  of  310  pages,  with  74  illus.  Cloth,  $1.75. 
It  is  a  concise  manual  of  three  hundred  pages,  I  the  recognition  of  compounds  due  to  pathological 
giving  an  excellent  summary  of  the  best  methods  conditions.  The  detection  of  poisons  is  treated 
of  analyzing  the  liquids  and  solids  of  the  body,  both  ;  with  sufficient  fulness  for  the  purpose  of  thestu- 
forthe  estimation  of  their  normal  constituents  and  i  dentor  practitioner. — Boston  Jt.  of  Chem.,  June,  '80. 


Lea  Brothers  &  Co.'s  Publications — Pharrn.,  Mat.  Med.,  Therap.  11 
BRUNTON,  T.  LAUDER,  M.D.,  D.Sc,  F.R.S.,  F.R.C.P., 

Lecturer  on  Materia  Medica  and  Therapeutics  at  St.  Bartholomews  Hospital,  London,  etc. 

A  Text-book  of  Pharmacology,  Therapeutics  and  Materia  Medica ; 
Including  the  Pharmacy,  the  Physiological  Action  and  the  Therapeutical  Usee  of  Drugs. 
In  one  handsome  octavo  volume  of  about  1000  pages,  with  188  illustrations.  Cloth,  §5.50  ; 
leather,  $6.50.     In  press. 

It  is  with  peculiar  pleasure  that  the  early  appearance  of  this  long  expected  work  is 
announced  by  the  publishers.  "Written  by  the  foremost  authority  on  its  subject  in  Eng- 
land, it  forms  a  compendious  treatise  on  materia  medica,  pharmacology,  pharmacy,  and 
the  practical  use  of  medicines  in  the  treatment  of  disease.  Space  has  been  devoted  to  the 
fundamental  sciences  of  chemistry,  physiology  and  pathology,  wherever  it  seemed  necessary 
to  elucidate  the  proper  subject-matter  of  the  book.  A  general  index,  an  index  of  diseases 
and  remedies,  and  an  index  of  bibliography  close  a  volume  which  will  undoubtedly  be  of 
the  highest  value  to  the  student,  practitioner  and  pharmacist. 

It  is  a  scientific  treatise  worthy  to  be  ranked  with 
the  highest  productions  in  physiology,  either  in 
our  own  or  any  other  language.     Everything  is 


practical,  the  dry,  hard  facts  of  physiology  bein^ 
pressed  into  service  and  applied  to  the  treatment 
of  the  commonest  complaints.  The  information 
is  so  systematically  arranged  that  it  is  available 
for  immediate  use.     The  index  is  so  carefully 


compiled  that  a  reference  to  any  special  point  is 
at  once  obtainable.  Dr.  Brunton  is  never  satisfied 
with  vague  generalities,  but  gives  clear  and  pre- 
cise directions  for  prescribing  the  various  drugs 
and  preparations.  We  congratulate  students  on 
being  at  last  placed  in  possession  of  a  scientific 
treatise  of  enormous  practical  importance.—  The 
Lancet,  June  27, 1885. 


PARRISH,  EDWARD, 

Late  Professor  of  the  Tlieory  and  Practice  of  Pharmacy  in  the  Philadelphia  College  of  Pharmacy. 
A  Treatise  on  Pharmacy :    designed  as  a  Text-book  for  the  Student,  and  as  a 
Guide  for  the  Physician  and  Pharmaceutist.     With  many  Formulae  and   Prescriptions. 
Fifth  edition,  thoroughly  revised,  by  Thomas  S.  "Wiegand,  Ph.  G.      In  one  handsome 
octavo  volume  of  1093  pages,  with  256  illustrations.     Cloth,  $5  ;  leather,  $6. 

No  thoroughgoing  pharmacist  will  fail  to  possess  I  Each  page  bears  evidence  of  the  care  bestowed 
himself  of  so  useful  a  guide  to  practice,  and  no  upon  it,  and  conveys  valuable  information  from 
physician  who  properly  estimates  the  value  of  an  the  rich  store  of  the  editor's  experience.  In  fact, 
accurate  knowledge  of  the  remedial  agents  em-  all  that  relates  to  practical  pharmacy— apparatus, 
ployed  by  him  in  daily  practice,  so  far  as  their  processes  and  dispensing— has  been  arranged  and 
miscibility,  compatibility  and  mosteffectivemeth-  described  with  clearness  in  its  various  aspects,  so 
ods  of  combination  are  concerned,  can  afford  to  as  to  afford  aid  and  advice  alike  to  the  student  and 
leave  this  work  out  of  the  list  of  their  works  of  to  the  practical  pharmacist.  The  work  is  judi- 
reference.  The  country  practitioner,  who  must  ciously  illustrated  with  good  woodcuts — American 
always  be  in  a  measure  his  own  pharmacist,  will  Journal  of  Pharmacy,  January,  1884. 
find  it  indispensable. — Louisville  Medical  yews,  There  is  nothing  to  equal  Parrish's  Pharmacy 
March  29, 1884.  in  this  or  any  other  language.— London  Pharma- 

This  well-known  work  presents  itself  now  based  I  ceutical  Journal. 
upon    the    recently  revised  new    Pharmacopoeia.  | 


HERMJlNX,  Dr.  L., 

Professor  (  i  in  Hie  University  of  Zurich. 

Experimental  Pharmacology.  A  Handbook  of  Methods  for  Determining  the 
Physiological  Actions  of  Drugs.  Translated,  with  the  Author's  permission,  and  with 
extensive  additions,  by  Eobert  Meade  Smith,  M.  D.,  Demonstrator  of  Physiology  in  the 
University  of  Pennsylvania.  In  one  handsome  12mo.  volume  of  199  pages,  with  32 
illustrations.     Cloth,  §1.50. 

MAISCH,  JOHX  M.7xn<vr.D7r 

Professor  of  Materia  Medica  and  Butanu  in  the  Philadelphia  College  of  Pharmacy. 


the 

and  Physicians.      New  (second)  edition.     In  one  handsome  royal 

.  with  242  illustrations.     Cloth,  $3.00.  Just  ready. 

This  work  contains  the  substance,— the  practical  excellent,  being  very  true  to  nature,  and  are  alone 

"kernel  of  the  nut"  picked  out,  so  that  the  stn-  worth  the  price  of  the  book  to  the  student.   Tothe 

dent  has  no  superfluous  labor.    He  can  confidently  practical  physician  and  pharmaci-t  it  is  a  valuable 

accept  what  this  work  places  before  him,  without  work  for  handy  reference  and  for  keeping  fresh 

any  fear  that  the  gist  of  the  matter  is  not  in  it.  in  the  memorv  the  knowledge  of  materia  medica 

Another  merit  is  that  the  drugs  are  placed  before  and  botany  already  acquired.     We  can  and  do 

him  in  such  a  manner  as  to  simplify  very  much  heartilv  recommend  it.— Medical  and  Surgical  Re- 

dy  of   them,  enabling  the  mind  to  grasp  porter,  Feb.  14,  1885. 
them  more  readily.    The   illustrations  are  mi 


BRUCE,  J.  MITCHELL,   M.  D.f  F.  R.  C.  P., 

ician  and  Lecturer  on  Matt  Via  Medina  and  Therapeutics  at  Charing  Cross  Hospital,  London. 

Materia  Medica  and  Therapeutics.  An  Introduction  to  Rational  Treat- 
ment, in  <>ne  pocket-size  12ino.  volume  of  555  pages.  Limp  cloth,  $1.50.  Just  ready. 
See  Student.--'  Series  of  Manuals,  page  3. 

GRIFFITH,  ROBERT  EGLESFIELD,  M.  D. 

A  Universal  Formulary,  containing  the  Methods  of  Preparing  and  Adminis- 
tering Officinal  and  other  Medicines.  The  whole  adapted  to  Physicians  and  Pharmaceut- 
ists. Third  edition,  thoroughly  revised,  with  numerous  additions,  by  John  M.  Maisch, 
Pliar.  D.,  Professor  of  Materia  Medica  and  Botany  in  the  Philadelphia  College  of  Pharmacy. 
In  one  octavo  volume  of  775  pages,  with  3S  illustrations.     Cloth,  $4.50;  leather,  $5.50. 


12        Lea  Brothers  &  Co.'s  Publications — Mat.  Med.,  Therap. 
STILLE,  A.,  M.  J).,  LL.  D.,  &  MAISCH,  J.  M.,  Thar.  Z)., 

Professor  Emeritus  of  the  Theory  and  Prae-  Prof,  of  Mat.  Med.  and  Botany  in  Phila. 

tice  of  Medicine  and  of  Clinical  Medicine 

in  tl-  \   of  Pennsylvania.  ran  Pharti  ion. 

The  National  Dispensatory:  Containing  the  Natural  History,  Chemistry,  l'har- 
macv.  Actions  and  Uses  of  Medicines,  including  those  recognized  in  the  Pharmacopoeias  of 
the  United  States,  Great  Britain  and  Germany,  with  numerous  references  to  the  French 
Codex.  Third  edition,  thoroughly  revised  and  greatly  enlarged.  In  one  magnificent 
imperial  octavo  volume  of  17G7  pages,  with  oil  tine  engravings.  Cloth,  $7.25; 
leather,  $8.00;  half  Russia,  open  back,  $9.00.  With  Denison's  "Ready  Reference  Index" 
$1.00  in  addition  to  price  in  any  of  above  styles  of  binding.     Just  ready. 

In  the  present  revision  the  authors  have  labored  incessantly  with  the  view  of  making 
the  third  edition  of  The  National,  Dispensatory  an  even  more  complete  represen- 
tative of  the  pharmaceutical  and  therapeutic  science  of  1884  than  its  first  edition  was  of 
that  of  1879.  For  this,  ample  material  has  been  afforded  not  only  by  the  new  United 
States  Pharmacopoeia, but  by  those  of  Germany  and  France,  which  have  recently  appeared 
and  have  been  incorporated*  in  the  Dispensatory,  together  with  a  large  number  of  new  non- 
officinal  remedies.  It  is  thus  rendered  the  representative  of  the  most  advanced  state  of 
American,  English,  French  and  German  pharmacology  and  therapeutics.  The  vast  amount 
of  new  and  important  material  thus  introduced  may  be  gathered  from  the  fact  that  the 
additions  to  this  edition  amount  in  themselves  to  the  matter  of  an  ordinary  full-sized  octavo 
volume,  rendering  the  work  larger  by  twenty-five  per  cent,  than  the  last  edition.  The 
Therapeutic  Index  (a  feature  peculiar  to  this  work),  so  suggestive  and  convenient  to  the 
practitioner,  contains  1600  more  references  than  the  last  edition — the  General  Index 
3700  more,  making  the  total  number  of  references  22,390,  while  the  list  of  illustrations 
has  been  increased  by  80.  Every  effort  has  been  made  to  prevent  undue  enlargement  of 
the  volume  by  having  in  it  nothing  that  could  be  regarded  as  superfluous,  yet  care  has 
been  taken  that  nothing  should  be  omitted  which  a  pharmacist  or  physician  could  expect 
to  find  in  it. 

The  appearance  of  the  work  has  been  delayed  by  nearly  a  year  in  consequence  of  the 
determination  of  the  authors  that  it  should  attain  as  near  an  approach  to  absolute  ac- 
curacy as  is  humanly  possible.  With  this  view  an  elaborate  and  laborious  series  of 
examinations  and  tests  have  been  made  to  verify  or  correct  the  statements  of  the  Pharma- 
copoeia, and  very  numerous  corrections  have  been  found  necessary.  It  has  thus  been  ren- 
dered indispensable  to  all  who  consult  the  Pharmacopoeia. 

The  work  is  therefore  presented  in  the  full  expectation  that  it  will  maintain  the 
position  universally  accorded  to  it  as  the  standard  authority  in  all  matters  pertaining  to 
its  subject,  as  registering  the  furthest  advance  of  the  science  of  the  day,  and  as  embody- 
ing in  a  shape  for  convenient  reference  the  recorded  results  of  human  experience  in  the 
laboratory,  in  the  dispensing  room,  and  at  the  bed-side. 

Comprehensive  in  scope,  vast  in  design  and  |  up  to  date.  The  work  has  been  very  well  done,  a 
Bplendid  in  execution.  The  National  Dispensatory  large  number  of  extra-pharmacopceia!  remedies 
may  bejustl  as  the  most  important  work    having  been  added  to  those  mentioned  in  previous 

of  its  kind  extant. — Louisville  Medical  News,  Dec.    editions. — London  Lancet,  Nov.  i':i,  ls>4. 
6,  18S  I.  Its  completeness  as  to  subjects,  the  comprehen- 

AVe  have  much  pleasure  in  recording  the  appear-  siveness  of  its  descriptive  language,  the  thorough- 
ance  of  a  third  edition  of  this  exc<  Hi  nt  work  of  ness  of  the  treatment  of  the  topics,  its  brevity  not 
reference.  It  is  an  admirable  abstract  ■■fall  that  sacrificing  the  desirable  features  of  information 
relates  to  chemistry,  pharmacy,  materia  medica,  for  which  such  a  work  is  needed,  make  this  vol- 
pharmacology  and  "therapeutics.  It  may  be  re-  time  a  marvel  of  excellence. — Pharmaceutical  .Re- 
garded as  embodying  the  Pharmacopoeias  of  the  cord,  Aug.  15, 1884 
civilized  nations  of  the  world,  all  being  brought  I 


FARQV1IARSOX,  ROBERT,  M.  D., 

Lecturer  on  Materia  Medica  at  St.  Mary's  Hospital  Medical  School. 

A  Guide  to  Therapeutics  and  Materia  Medica.  Third  American  edition, 
specially  revised  by  the  Author.  Enlarged  and  adapted  to  the  U.  S.  Pharmacopoeia  by 
Frakk  Woodbtjky,  M.  D.     In  one  handsome  12mo.  volume  of  524  pages.     Cloth,  $2.2o. 

Dr.  Farquharson's  Therapeutics  is  constructed  umned  pages— one  side  containing  the  recognized 

upon  a  plan  which  brings  before  the  reader  all  tin  physiological  action  of  the  medicine,  andthe  other 

essential  points  with  reference  to  the  properties  of  the  disease  in  which  observers  (who  are  nearly  al- 

drugs.    It  impresses  these  upon  him  in  such  a  way  ways  mentioned)  have  obtained  from  it  good  re- 

as  bo  enable  him  to  take  a  clear  view  of  the  actions  suits— make  a  very  good  arrangement    The  early 

of  medicines    and  the  disordered  conditions  in  chapter  containing  rules  for  prescribing  is  excel- 

which  they  must  prove  useful.    The  double-col-  lent.—  '                       and  Surg.  Journal,  Dec.  1882. 

STILLE,  ALFRED,  31.  J).,  LL.  1)., 

Professor  of  Them  y  <i-,<i  Pt  actice  of  Med.  find  of  Clinical  Mid.  in  the  Univ.  ofPemna. 
Therapeutics  and  Materia  Medica.     A  Systematic  Treatise  on  the  Action  and 
Uses  of  Medicinal   Agents,  including  their    Description    and    History.     Fourth    edition, 
revised  and  enlarged.     In  two  larg-e  and  handsome  octavo  volumes,  containing  193b'  page*. 
Cloth,  $10.00;   leather.  $12.00;   very  handsome  ball  Russia,  raised  bands,  $13.00. 

We  can  hardly  admit   that  it  has  a  rival  in  the     in  pharmacodynamics,  but  as  by  far  the  most  conv 
multitude  of   its   citations  and  ihc  fulness   of  its  '  pi cte  treatise  upon  the  clinical  and  practical  side 
research  into  clinical  histories, and  wemust  assign     of  the  question. — Boston  Medical  and  Surgical  Jc*rr- 
it  a  place  in  the  physician's  library;  not,  indeed,     nal,  Nov.  5, 1874. 
as  fully  represent  mgt  he  present  stale  of  knowledge 


Lea  Brothers  &  Co.'s  Publications — Pathol.,  Histol. 


13 


COATS,  JOSEPH,  M.  D.,  F.  F.  P.  S., 

Pathologist  to  tlu  Western  Infirmary. 

A  Treatise  on  Pathology.     In  one  very  handsome  octavo  volume  of  829  pages, 
with  339  beautiful  illustrations.     Cloth,  $5.50;  leather,  $6.50. 

The  work  before  us  treats  the  subject  of  Path-  condition  effected  in  structures  by  disease,  and 
ologv  more  extensively  than  it  is  usually  treated  points  out  the  characteristics  of  various  morbid 
in  similar  works.  Medical  students  as  well  as  agencies,  so  that  they  can  be  easily  recognised.  But, 
physici  lesireawork  for  study  or  refer-    not  limited  to  morbid  anatomy.it  explains  fully  how 

ence,  that  treats  the  subjects  in  the  van  le  functions  of  organs  are  disturbed  by  abnormal 

partments  in  a  very  thorough  manner,  but  without    conditions.    There  is  nothing  belonging  to  its  de- 
prolixity,  will  certainly  give  thi<  ,,ne  the  prefer-    partment  of  medicine  that  is  not  as  fully  elucidated 
ence  to  any  with  which  we  are  acquainted.    It  sets    as  our  present  knowledge  will  admit.—  Cincinnati 
forth  the  most  recent  discoveries,  exhibits,  in  an     Medical  News,  Oct.  1883. 
interesting  manner,   the  changes  from  a  normal 


GREEX,  T.  HEXRY,  31.  D., 

J.  ,-■  Anatomy  at  Charing-Cross  Hospital  Medical  School,  London. 

Pathology  and  Morbid  Anatomy.  Fifth  American  from  the  sixth  revised 
and  enlarged  English  edition.  In  one  very  handsome  octavo  volume  of  4S2  pages,  with 
150  line  engravings.     Cloth,  $2.50. 

The  fact    that  this  well-known  treatise  has   So    Xo  work  in  the  English  language  is  so  admirably 
rapidly  reached  its  sixth  edition  is  a  strong  evi-    adapted  to  the  wai  student  and   practi- 

dence  of  it^  popularity.    The  audio.  q-    tioner  as  this,  and  we  would  recommend  it  most 

gratulated  upon  the  thoroughness  with  which  he    earnest!;.  le  Journal  of  Medir 

has  prepared  this  work.     It  is  thoroughly  abreast    cine  ar.d  Surgery,  Nov.  1884. 
with  all  the  most  recent  advances  in  pathol" 

WOODHEAD,  G.  SIMS,  M.   />.,  F.  R.  C.  P.  E., 

Demonstrator  of  Pathology  in  the  University  of  Edinburgh. 
Practical  Pathology.     A  Manual   for  Students  and  Practitioners, 
tiful  octavo  volume  of  497  pages,  with  136  exquisitely  colored  illustrations. 


It  forms  a  real  guide  for  the  student  and  practi- 
tioner who  is  thoroughly  In  earnest  in  his  en- 
deavor to  see  for  himself  anil  do  for  himself.  To 
the  laboratory  student  it  will  be  a  helpful  com- 
panion, and  all  those  who  may  wish  to  familiarize 
themselves  with  modern  methods  of  examining 
morbid  tissues  are  strongly  urged  to  | 
themselves  with  this  manual.  The  numerous 
drawings  arc  not  fancied  pictures,  or  merely 
schematic  diagrams,  but  they  represent  faithfully 
the  actual   images  seen  under  the    microscope. 


In  one  beau- 
Cloth,  $6.00. 

The  author  merits  all  praise  for  having  produced 
OTk.— Medical  Record,  May  31,  1884. 
It  l-  manifestly  the  product  of  one  who  has  him- 
self travel  led  over  the  whole  field  and  who  is  skilled 

rely  in  the  art  of  histology,  but  in  the 
vation  and  interpretation  of  morbid  changes.  The 
-  -me  to  command  a  wide  circulation.  It 
should  do  much  to  encourage  the  pursuit  of  path- 
jince  such  advantages  in  hi-tological  study 
have  never  before  been  offered. —  The  Lancet,  Jan. 
5,  1884. 


SCHAFER,  EDWARD  A.,  F.  R.  S., 

u  University  College,  London. 

The  Essentials  of  Histology.     In  one  octavo  volume  of  246  pages,  with 
281  illustrations.     Cloth,  $2.25.     Shortly. 


CORJSTIL,  V.,  and  RAXYIER,  L., 

Prof,  in  the  Far'ilf'i  of M  Prof,  in  the  College  of  France. 

A  Manual  Of  Pathological  Histology.  Translated,  with  notes  and  additions, 
by  E.  ().  Shakespeare,  M.  D.,  Pathologist  and  Ophthalmic  Sunreon  to  Philadelphia 
Hospital,  and  by  J.  Henry  C.  Semes,  M.  I'.,  Demonstrator  of  Pathological  Histology  in 
the  university  of  Pennsylvania,  la  one  very  handsome  octavo  volume  of  800  [  ages,  with 
360  illustrations.    Cloth,  $5.50  ;  leather,  $6.50;  half  Russia,  raised  bands,  $7. 

KLEIX,  E„  M.  D.,  F.  R.  S., 

al  Anat.  and  Phys.  in  the  Med.  School  of  St.  Bartholomew's  Hasp.,  London. 

Elements  of  Histology.  In  one  pocket-size  12mo.  volume  of  360  pages,  with  181 
tllns.    Limp  cloth,  red  edges,  $1.50.  of  Manuals,  page  3. 

Ugh  an  elein  ,  jt  is  by  no  < 

superficial  or  incomplete,  for  the  author  | 

guage  nearly  all  the  fundamental  facts 
regarding  the  microscopic  structure  of   I 


The  illustrations  are  numerous  and  excellent.    We 
commend  L>r.   Klein's   1  :   heartily  to 

the  student.— Medical  Pecord,  Dec.  1, 1883. 


PEPPER,  A.  J.,  M.  B.,  M.  S.,  F.  R.  C.  S., 

Hospital,  London. 

Surgical  Pathology.     In  one  pocket-size  12mo.  volume  of  511  pages,  with  81 
illustrations.  Limp  cloth,  re 

It  is  not  pretentious,  but  it  will   -  ustrated.    The  student  will  find  in  it  nothing 

in gly  well  as  a  book  of  reference.    It  embodies  a  that  is  unnecessary.    The  list                       -vers 

gr>-at  deal  of  matter,  extending  over  the  whole    the  whole  range  of  surgery.    The  I k  supplies  a 

field  of  surgical  pathology.    Its  form  is  practical,  very  manifest  wan'                              •   with  suc- 

its    language    is  clear,   and   the  information   -•  :  tress. — New  York  Medical  Journal,  May  31, 1684 
forth   is   well-arranged,    well-indexed   and  well- 


BCHAFER'S  PRACTICAL  HISTOLOGY.  In  one  I  OGY.  Translated  by  Joseph  Lanrr,  M.  D.  In  one 
handsome  royal  12mo.  volun  th  I  volume,   very    large    imperial    quarto,  with   33» 

40  illl  in  and   colored   and   dr«- 

GLUGE'S  ATLAS  OF  PATHOLOGICAL  HISTOL-  |  cru'tivc  letter-press.     Cloth,  $4.00 


14 


Lea  Brothers  &  Co.'s  Publications — Practice  of  Med. 


FLINT,  AUSTIN,  M.  !>., 

Prof,  of  the  Principles  and  Practice  of  Med.  and  of  Clin.  Med.  in  BeUevue  Hospital  Medical  College,  N.  Y. 

A  Treatise  on  the  Principles  and  Practice  of  Medicine.  Designed  for 
the  use  of  Students  and  Practitioners  of  Medicine.  With  an  Appendix  on  the  Researches 
of  Koch,  and  their  bearing  on  the  Etiology,  Pathology,  Diagnosis  and  Treatment  of 
Phthisis.  Fifth  edition,  revised  and  largely  rewritten  In  one  large  and  closely -printed 
octavo  volume  of  1160  pages.     Cloth,  $5.50;  leather,  $6.50;  half  Russia,  $7. 

Koch's  discovery  of  the  bacillus  of  tubercle  gives  promise  of  being  the  greatest 
boon  ever  conferred  by  science  on  humanity,  surpassing  even  vaccination  in  its  benefits  to 
mankind.  In  the  appendix  to  his  work,  Professor  Flint  deals  with  the  subject  from  a 
practical  standpoint,  discussing  its  bearings  on  the  etiology,  pathology,  diagnosis,  prog- 
nosis and  treatment  of  pulmonary  phthisis.  Thus  enlarged  and  completed,  this  standard 
work  will  be  more  than  ever  a  necessity  to  the  physician  who  duly  appreciates  the  re- 
sponsibility of  his  calling. 


A  well-known  writer  and  lecturer  on  medicine 
recently  expressed  an  opinion,  in  the  highest  de- 
gree complimentary  of  the  admirable  treatise  of 
Dr.  Flint,  and  in  eulogizing  it,  he  described  it  ac- 
curately as  "  readable  and  reliable."  No  text-book 
is  more  calculated  to  enchain  the  interest  of  the 
student,  and  none  better  classifies  the  multitudi- 
nous subjects  included  in  it.  It  has  already  so  far 
won  its  way  in  England,  that  no  inconsiderable 
number  of  men  use  it  alone  in  the  study  of  pure 
medicine;  and  we  can  say  of  it  that  it  is  in  every 
way  adapted  to  serve,  not  only  as  a  complete  guide, 
but  also  as  an  ample  instructor  in  the  science  and 
practice  of  medicine.  The  style  of  Dr.  Flint  is 
always  polished  and  engaging.  The  work  abounds 
in  perspicuous  explanation,  and  is  a  most  valuable 
text-book  of  medicine. — London  Medical  News. 


This  work  is  so  widely  known  and  accepted  as 
the  best  American  textbook  of  the  practice  of 
medicine  that  it  would  seern  hardly  worth  while  to 
give  this,  the  fifth  edition,  anything  more  than  a 
passing  notice.  But  even  the  most  cursory  exami- 
nation shows  that  it  is,  practically,  much  more 
than  a  revised  edition ;  it  is,  in  fact,  father  a  new 
work  throughout.  This  treatise  will  undoubtedly 
continue  to  hold  the  first  place  in  the  estimation 
of  American  physicians  and  students.  No  one  of 
our  medical  writers  approaches  Professor  Flint  in 
clearness  of  diction,  breadth  of  view,  and,  what  we 
regard  of  transcendent  importance,  rational  esti- 
mate of  the  value  of  remedial  agents.  It  is  thor- 
oughly practical,  therefore  pre-eminently  the  book 
for  American  readers. — St.  Louis  Clin.  Rec,  Mar.  '81. 


HARTSHORNE,  HENRY,  31.  !>.,  LL.  !>., 

Lately  Professor  of  Hygiene  in  the  University  of  Pennsylvania. 

Essentials  of  the  Principles  and  Practice  of  Medicine.  A  Handbook 
for  Students  and  Practitioners.  Fifth  edition,  thoroughly  revised  and  rewritten.  In  one 
royal  12mo.  volume  of  669  pages,  with  144  illustrations.     Cloth,  $2.75 ;  half  bound,  $3.00. 


Within  the  compass  of  GOO  pages  it  treats  of  the 
history  of  medicine,  general  pathology,  general 
symptomatology,  and  physical  diagnosis  (including 
laryngoscope,  ophthalmoscope,  etc.),  general  ther- 
apeutics, nosology,  and  special  pathology  and  prac- 
tice. There  is  a  wonderful  amount  of  information 
contained  in  this  work,  and  it  is  one  of  the  best 
of  its  kind  that  we  have  seen. — Glasgow  Medical 
Journal,  Nov.  1S82. 

An  indispensable  book.  No  work  ever  exhibited 
a  better  average  of  actual  practical  treatment  than 


this  one;  and  probably  not  one  writer  in  our  day 
had  a  better  opportunity  than  Dr.  Hartshorne  for 
condensing  all  the  views  of  eminent  practitioners 
into  a  12mo.  The  numerous  illustrations  will  be 
very  useful  to  students  especially.  These  essen- 
tials, as  the  name  suggests,  are  not  intended  to 
supersede  the  text-books  of  Flint  and  Bartholow, 
but  they  are  the  most  valuable  in  affording  the 
means  to  see  at  a  glance  the  whole  literature  of  any 
disease,  and  the  most  valuable  treatment. — Chicago 
Medical  Journal  and  Examiner,  April,  1882. 


BRISTOWE,  JOHN  SYER,  M.  2>.,  F.  R.  C.  P., 

Physician  and  Joint  Lecturer  on  Medicine  at  St.  Thomas'1  Hospital. 

A  Treatise  on  the  Practice  of  Medicine.  Second  American  edition,  revised 
by  the  Author.  Edited,  with  additions,  by  James  H.  Hutchinson,  M.D.,  physician  to  the 
Pennsylvania  Hospital.  In  one  handsome  octavo  volume  of  1085  pages,  with  illustrations. 
Cloth,  $5.00 ;  leather,  $6.00 ;  very  handsome  half  Russia,  raised  bands,  $6.50. 


The  reader  will  find  every  conceivable  subject 
connected  with  the  practice  of  medicine  ably  pre- 
sented, in  a  style  at  once  clear,  interesting  and 
concise.    The  additions  made  by  Dr.  Hutchinson 


are  appropriate  and  practical,  and  greatly  add  to 
its  usefulness  to  American  readers. — Buffalo  Med- 
ical and  Surgical  Journal,  March,  1880. 


WATSON,  SIR  THOMAS,  M.  !>., 

Late  Physician  in  Ordinary  to  the  Queen. 

Lectures  on  the  Principles  and  Practice  of  Physic.  A  new  American 
from  the  fifth  English  edition.  Edited,  with  additions,  and  190  illustrati  ms,  by  Henry 
Hartshorne,  A.  Si.,  M.  D.,  late  Professor  of  Hygiene  in  the  University  of  Pennsylvania. 
In  two  large  octavo  volumes  of  1840  pages.     Cloth,  $9.00  ;  leather,  $11.00. 


LECTURES  ON  THE  STUDY  OF  FEVER.  By 
A.  Hudson,  M.  D.,  M.  R.  I.  A.  In  one  octavo 
volume  of  308  pages.    Cloth,  $2.50. 

STOKES'  LECTURES  ON  FEVER.  Edited  by 
John  William  Moore,  M.  D.,  F.  K.  Q.  C.  P.  In 
one  octavo  volume  of  280  pages.    Cloth,  $2.00. 


A  TREATISE  ON  FEVER.  By  Robert  D.  Lyons, 
K.  C.  C.     In  one  8vo.  vol.  of  354  pp.    Cloth,  $2.25. 

LA  ROCHE  ON  YELLOW  FEVER,  considered  in 
its  Historical,  Pathological,  Etiological  and 
Therapeutical  Relations.  In  two  large  and  hand- 
some octavo  volumes  of  1468  pp.    Cloth,  $7.00. 


A   CENTURY  OF  AMERICAN  MEDICINE,  1776—1876.     By  Drs.  E.  H.  Clarke,  H.  J. 
Bigelow,  S.  D.  Gross,  T.  G.  Thomas,  and  J.  S.  Billings.    In  one  12mo.  volume  of  370  pages.    Cloth,  $2.25. 


Lea  Brothers  &  Co.'s  Publications — Systems  of  Med.  15 

For  Sale  by  Subscription  Only. 


A  System  of  Practical  Medicine. 

BY  AMERICAN  AUTHORS. 

Edited  by  WILLIAM   PEPPER,  M.  D.,  LL.  D., 

PROVOST  AND   PROFESSOR   OP  THE  THEORY  AND   PRACTICE  OP   MEDICINE  AND   OF 
CLINICAL  MEDICINE  IN  THE  UNIVERSITY  OF  PENNSYLVANIA, 

Assisted  by  Louis  Starr,  M.  D.,  Clinical  Professor  of  the  Diseases  of  Children  in  the 
Hospital  of  the  University  of  Pennsylvania. 

In  five  imperial  octavo  volumes,  containing  about  1100  pages  each,  with  illustrations.     Price  per 
volume,  cloth,  $5;    leather,  $6;    half  Russia,  raised  bands  and  open  back,  $7.      Volume  I. 
(General  Pathology,  Sanitary  Science  and  General  Diseases)  contains  1094  pages, 
with  24  illustrations  and  is  just  ready.      Volume  II.  (General  Diseases  [con- 
tinued] and  Diseases  of  the   Digestive   System)  contains   1312  pages, 
with  27  illustrations,  and  is  just  ready.     Volume  III.  (Diseases  of 
,  the  Respiratory,  Circulatory  and  Haematopoietic  Systems) 
containing  about  10-50  pages,  will  be  ready  October  1st, 
and  the  subsequent  volumes  at  intei~vals  of  four 
months  thereafter. 

The  publishers  feel  pardonable  pride  in  announcing  this  magnificent  work.  For 
three  years  it  has  been  in  active  preparation,  and  it  is  now  in  a  sufficient  state  of  forward- 
ness to  justify  them  in  calling  the  attention  of  the  profession  to  it  as  the  work  in  which 
for  the  first  time  American  medicine  is  thoroughly  represented  by  its  worthiest 
teachers,  and  presented  in  the  full  development  of  the  practical  utility  which  is  its 
preeminent  characteristic.  The  most  able  men — from  the  East  and  the  West,  from  the 
North  and  the  South,  from  all  the  prominent  centres  of  education,  and  from  all  the 
hospitals  which  afford  special  opportunities  of  study  and  practice — have  united  in 
generous  rivalry  to  bring  together  this  vast  aggregate  of  specialized  experience. 

The  distinguished  editor  has  so  apportioned  the  work  that  each  author  has  had 
assigned  to  him  the  subject  which  he  is  peculiarly  fitted  to  discuss,  and  in  which  his  views 
will  be  accepted  as  the  latest  expression  of  scientific  and  practical  knowledge.  The 
practitioner  will»therefore  find  these  volumes  a  complete,  authoritative  and  unfailing  work 
of  reference,  to  which  he  may  at  all  times  turn  with  full  certainty  of  finding  what  he  needs 
in  its  most  recent  aspect,  whether  he  seeks  information  on  the  general  principles  of  medi- 
cine, or  minute  guidance  in  the  treatment  of*  special  disease.  So  wide  is  the  scope  of  the 
work  that,  with  the  exception  of  midwifery  and  matters  strictly  surgical,  it  embraces  the 
whole  domain  of  medicine,  including  the  departments  for  which  the  physician  is  accustomed 
to  rely  on  special  treatises,  such  as  diseases  of  women  and  children,  of  the  genito-urinary 
organs,  of  the  skin,  of  the  nerves,  hygiene  and  sanitary  science,  and  medical  ophthalmology 
and  otology.  Moreover,  authors  have  inserted  the  formulas  which  they  have  found  most 
efficient  in  the  treatment  of  the  various  affections.  It  may  thus  be  truly  regarded  as  a 
Complete  Library  of  Practical  Medicine,  and  the  general  practitioner  possessing  it 
may  feel  secure  that  he  will  require  little  else  in  the  daily  round  of  professional  duties. 

In  spite  of  every  effort  to  condense  the  vast  amount  of  practical  information  fur- 
nished, it  has  been  impossible  to  present  it  in  less  than  5  large  octavo  volumes,  containing 
aboul  5500  beautifully  printed  pages,  and  embodying  the  matter  of  about  15  ordinary 
octavos.     Illustrations  arc  introduced  wherever  they  serve  to  elucidate  the  text. 

As  material  for  the  work  is  substantially  complete  in  the  hands  of  the  editor,  the  pro- 
fession may  confidently  await  the  appearance  of  the  remaining  volumes  upon  the  dates 
above  specified.  A  detailed  prospectus  of  the  work  will  be  sent  to  any  address  on  appli- 
cation to  the  publishers. 

It  is  a  large  undertaking,  but  quite  justifiable  in  this  country  as  authorities  on  the  particular  topics 
the  ease  of  a  progressive  nation  like  the  United  oo  which  they  deal,  whilst  the  others  show  by  the 
States.  At  any  rate,  if  we  may  judge  of  future  way  they  have  handled  their  subjects  that  they 
volumes  from  the  first  it  will  be  justified  by  the  ,  are  fully  equal  to  the  task  they  had  undertaken, 
result.  We  have  nothing  but  praise  to  bestow  •  *  *  A  work  which  we  cannot  doubt  will  make 
upon  the  work.  The  articles  are  the  work  of  a  lasting  reputation  for  itself.— London  Medical 
writers,  many  of  whom  are  already  recognized  in  j  Times  and  Gazette,  May  9,  1885. 

REYNOLDS,  J.  BUS8JEZZ,  M.  I)., 

Professor  of  the  Principled  and  Practice  of  Medicine  in  University  College,  London. 
A  System  Of  Medicine.  With  notes  and  additions  by  Henry  IIartshorne, 
A.  M.,  M.  D.,  late  Professor  cf  Hygiene  in  the  University  of  Pennsylvania.  In  three  large 
and  handsome  octavo  volumes,  containing  3056  double-columned  pages,  with  317  illustra- 
tions. Price  per  volume,  cloth,  $5.00 ;  sheep,  $6.00 ;  very  handsome  half  Russia,  raised  bands, 
$6.50.     Per  set,  cloth,  $15;  leather,  $18;  half  Russia,  $19.50.     Sold  only  by  subscript!'    ' 


16  Lea  Brothers  &  Co.'s  Publications — Clinical  Med.,  etc. 

STILL  E,  ALFRED,  31.  T>.,  LL.  I)., 

I'r  i   ssor  Emeritus  of  the  Theory  ayid  Practice  of  Med.  and  of  Clinical  Med.  in  the  Univ.  of  Penna. 

Cholera:  Its  Origin,  History, Causation, Symptoms,  Lesions,  Prevention  and  Treat- 
ment. In  one  handsome  12mo.  volume  of  163  pages,  with  a  chart.  Cloth,  $1.25.  Just  ready. 

The  threatened  importation  of  cholera  into  the  country  renders  peculiarly  timely 
this  work  of  an  authority  upon  the  subject  so  eminent  as  Professor  Stille.  The  history 
of  previous  epidemics,  their  modes  of  propagation,  the  vast  recent  additions  to  our 
knowledge  of  the  causation,  prevention  and  treatment  of  the  disease,  all  have  been  handled 
so  skilfully  as  to  present  with  brevity  the  information  which  every  practitioner  should 
possess  in   advance  of  a  visitation. 


This  timely  little  work  is  full  of  the  learning 
and  good  judgment  which  marks  all  that  cornea 
from  the  pen  of  its  distinguished  author.  What 
he  has  to  say  on  treatment  is  characterized  by 
his  usual  caution  and  his  well-known  preference 


for  a  rational  system.  Altogether,  the  monograph 
is  one  that  will  have  an  excellent  influence  on  the 
professional  minct.— Medical  and  Surgical  Reporter, 
August  1,  1885.     q. 


FLINT,  AUSTIN,  31.  TJ. 

Clinical  Medicine.  A  Systematic  Treatise  on  the  Diagnosis  and  Treatment  of 
Diseases.  Designed  for  Students  and  Practitioners  of  Medicine.  In  one  large  and  hand- 
some  octavo   volume   of  799  pages.     Cloth,  $4.50;  leather,  $5.50 ;  half  Russia,  $6.00. 

It  is  here  that  the  skill  and  learning  of  the  great 
clinician  are  displayed.  He  has  given  us  a  store- 
house of  medical  knowledge,  exeellentfor  the  stu- 
dent, convenient  for  the  practitioner,  the  result  of 
a  long  life  of  the  most  faithful  clinical  work,  col- 
lected by  an  energv  as  vigilant  and  systematic  as 
untiring,  and  weigbed  by  a  judgment  no  less  clear 
than  his  observation  is  close. — Archives  of  Medicine, 
Dec.  1879. 

To  give  an  adequate  and  useful  conspectus  of  the 
extensive  field  of  modern  clinical  medicine  is  a  task 
of  no  ordinary  difficulty;  but  to  accomplish  this  con- 


sistently with  brevity  and  clearness,  the  different 
subjects  and  their  several  parts  receiving  the 
attention  which,  relatively  to  their  importance, 
medical  opinion  claims  for  them,  is  still  more  diffi- 
cult. This  task,  we  feel  bound  to  say,  has  been 
executed  with  more  than  partial  success  by  Dr. 
Flint,  whose  name  is  already  familiar  to  students 
of  advanced  medicine  in  this  country  as  (hat  of 
the  author  of  two  works  of  great  merit  on  special 
subjects,  and  of  numerous  papers  exhibiting  much 
originality  and  extensive  research. — 7  he  Dublin 
Journal,  Dec.  1879. 


By  the  Same  Author. 
Essays  on  Conservative  Medicine  and  Kindred  Topics.  In  one  very  hand- 
some royal  12ino.  volume  of  210  pages.     Cloth,  $1.38. 

BROADBENT,  W .  JBT.,  M.  !>.,  F.  R.  C.  P., 

Physician  to  and  Lecturer  on  Medicine  at  St.  Mary's  Hospital. 
The  Pulse.     In  one  12rno.  volume.     See  Series  of  Clinical  il/cmua/s,.  page  3. 

SCSREIBER,  DR.  JOSEPH. 

A  Manual  of  Treatment  by  Massage  and  Methodical  Muscle  Ex- 
ercise. Translated  by  Walter  Mendelson,  M.  D.,  of  New  York.  In  one  handsome 
octavo  volume  of  about  300  pages,  with  about  125  fine  engravings.     Preparing. 

FINLAYSON,  J AWES^M7lJ7, Editor, 

Physician  and  Lecturer  on  Clinical  Medicine  in  the  Glasgow  Western  Infirmary,  etc. 
Clinical  Diagnosis.  A  Handbook  for  Students  and  Practitioners  of  Medicine. 
With  Chapters  by  Prof.  Gairdner  on  the  Physiognomy  of  Disease ;  Prof.  Stephens^  on 
Diseases  of  the  Female  Organs;  Dr.  Robertson  on  Insanity;  Dr.  Gemmell  on  Physical 
Diagnosis;  Dr.  Coats  on  Laryngoscopy  and  Post-Mortem  Examinations,  and  by  the  Editor 
on  Case-taking,  Family  History  and  Symptoms  of  Disorder  in  the  Various  Systems.  In 
one  handsome  12rno.  volume  of  546  pages,  with  85  illustrations.     Cloth,  $2.63. 

FENWICK,  SA3TUEL,  M.  D., 

Assistant  Physician  to  the  London  Hospital. 

The  Student's  Guide  to  Medical  Diagnosis.  From  the  third  revised  and 
enlarged  English  edition.  In  one  very  handsome  royal  12mo.  volume  of  328  pages,  with 
87  illustrations  on  wood.     Cloth,  $2.25. 

TANNER,  THOMAS  HAWKES,  31.  D. 

A  Manual  of  Clinical  Medicine  and  Physical  Diagnosis.  Third  American 
from  the  second  London  edition.  Revised  and  enlarged  by  Tilbury  Fox,  M.  D. 
In  one  small  12mo.  volume  of  362  pages,  with  illustrations.     Cloth,  $1.50. 

FOTHERGILL,  J.  31.,  M.  D.,  Edin.,  M.  R.  C.  P.,  Lond., 

Physician  to  the  City  of  London  Hospital  for  Diseases  of  the  Chest. 

The  Practitioner's  Handbook  of  Treatment ;  Or,  The  Principles  of  Thera- 
peutics.  New  edition.     In  one  octavo  volume.     Preparing. 


STURGES'  INTRODUCTION  TO  THE  STUDY 
OF  CLINICAL  MEDICINE.  Being  a  Guide  to 
the  Investigation  of  Disease.  In  one  handsome 
12mo.  volume  of  127  pages.    Cloth,  $1.25. 


DAVIS'  CLINICAL  LECTURES  ON  VARIOUS 
IMPORTANT  DISEASES.  By  N.  S.  Davi& 
M.  D.  Edited  by  Frank  H.  Davis,  M.  D.  Second 
edition.    12mo.  287  pages.    Cloth,  $1.75. 


Lea  Brothers  &  Co.'s  Publications — Hygiene,  Elect  r.,  Pract.        17 


RICHAR&SOX,  B.  W..  M.A.,  M.D.,  LL.  L>.,  F.R.S.,  F.S.A. 

Fellow  of  the  Roi/al  Coll  eye  of  V  udon. 

Preventive  Medicine.     In  one  octavo  volume  of  729  pages.    Cloth,  $4;  leather, 
$ 5 ;  very  handsome  half  Russia,  raided  bam 

Dr.                       has  succeeded   in  producing  a  the  question  of  disease  is  comprehensive,  master!/ 

work  which  is  elevated  in  conception,  comprehen-  and  fully  abreast  with  the                             :nowt 

sive  i'                     ntific  in  character, systematic  in  ed 

arrangement,  ami  which  is  written  in  a  clear,  con-  advised  are  ac                                                 i  —The 

manner,    Ii 

(acuity  or  extracting  the  pith  of  what  is  kn  >     ok  that  will  surely  find  a  place  on  the 

the  subject,  and  of  presenting  it  in  a  most  simple,  table   of  every    progressive    p                    !  i    the 

Intelligent  and  practical  form.    Thi  uchto 

no  similar  work  written  for  the  general   public  prevent  as  to  cure  dig 

thatcontains  such  acomplete, reliable  and  instruc-  — Bosto                                                             1884. 

fcive  collection  of  data  upon  the  diseases  common  Thetri                                                         ;,  valu- 

to  the  race,  their  origins,  causes,  and  ,:  e  nrn  asures  i  able  hygienic  information.— .1/                      -rgioal 

for  their  prevention.    The  descriptions  of  diseases  Reporter,  Feb.  23, 1884. 
are  clear,  chaste  and  scholarly  ;  the  discussion  of  | 


BARTHOLOW,  ROBERTS,  A.  M.9  M.  D.,  LL.  J)., 

Prof,  of  Materia  Mcdica  and  General  Therapeutics  in  the  Jtfft 

Medical  Electricity.    A  Practical  Treatise  on  the  Applications  of  Electricity 
to  Medicine  and  Surgery.     Second  edition,     in  one  very  handsome  octavo  volume  i 
pages,  with  109  illustrations.     Cloth,  $2.50. 

The  second  edition  of  this  work  following  so       A  most  excellent  work,  addressed  by  a  practl- 
soon  upon  the  first  would  in  itself  i  a    tioner  to  his  :■  itioners,  and  therefore 

sufficient  announcement;  nevertheless,  the  text  thoroughly  practical.  The  work  now  Kef. re  us 
has  been  so  considerably  revised  a  exceptional  merit  of  cl<  ig  out 

and  so  much  enlarged  by  the  addition  of  new  mat-  where  the  benefits  to  be  derived  from  electricity 
ter,  that  we  cannot  ignise  a  vast  improve-    must  come.    It  contains  ail  and  everything  that 

ment  upon  the  former  work.  The  author  has  pre-  the  practitioner  needs  in  order  to  understand  in- 
pared  his  work  for  students  and  practitioner-— for  ,  telligently  the  nature  and  laws  of  the  agent  he  is 
those  who  have  neve'  acquainted  th<  .    use  of,  and   for   i: 

the  subject,  or,  having  done  so,  find  that  after  a  |  practice.    In  a  condensed,  prac  t  pre- 

time  their  knowledge  needs  refreshing.    We  thin  the  physician  all  that  lie  would  wish  to 

he  has  accomplished  t .' i i  —  object.  The  book  Is  not  ,  rememberafterperusinga  whole  library  or.  medical 
too  voluminous,  but  is  thoroughly  practical,  Bim- 1  electricity,  including  the  results  -t  in- 

pie,  complete  and  comprehensible.  It  is,  more-  vestieations.  It  is  the  book  for  tic  practitioner, 
over,  replete  with  numerous  illustrations  of  instru-  :  and  the  necessity  for  .  |  tion  provi 

ments,  appliances,  etc. — Medical  Record,  .November  ,  it  has  been  appreciated  by  the  profession. — Ptiysi- 

|  cian  and  Sun/con,  Dec.  i 


THE  YEAR-BOOK  OF  TREATMENT. 

A  Comprehensive  and  Critical  Review  for  Practitioners  of  Medi- 
cine.    In  one  12mo.  volume  of  320  pages,  bound  in  limp  cloth,  with  red  edges,  : 

This  work  j  -t  >  ■-*  1 1 1  ~  to  the  practitioner  not  only  a  complete  classified  account  of  all 
the  more  important  advances  made  in  the  treatment  of  Disease  during  the  year  ending 
Sept.  30,  L884.  but  also  a  critical  estimate  of  the  same  by  a  competent  authority.  Each 
department  of  practice  has  been  fully  and  concisely  treated,  and  into  the  COnsideratl 
each  subject  enter  such  allusions  to  recent  pathological  and  clinical  work  as  bear  directly 
upon  treatment.  As  the  medical  literature  of  all  countries  has  been  placed  under  contri- 
bution, the  references  given  throughout  the  work,  together  with  the  separate  index 
subjects  and  authors,  will  serve  as  a  guide  for  those  who  desire  to  investigate  any  thera- 
d  topic  at  greater  Length. 

In  a  few  moments  the  busy  practitioner  oan  re-  I  can  Journal  of  ti 
fresh  his  mind  as  to  the  principal  advances  in'     It  is  a  complete  account  of  tin.  more  important 
treatment  for  a  year  past.    This  kind  of  work  is    advances  mad:    In  the  treatment  Ex- 

feculiarly  useful  at  the  present  time,  when  current    treme  pains  have  i>.  i  ly  in 

Iterature  i-  teeming  with  innumerable  so-called    thi 

advances,  of  which  the  practitioner  ha- not  time    writer,  and  the  detail-  ol  I 

to  determine  the  value.    B«-re  he  has,  collected    the  principle  points  about  the b 
from  many  sources, a  rlmmi  of  the  theories  ami    yet  concise  langnagi 

rhich  are  new,  either  entirely  or  in  part,  the  I  formed  his  duty,  and  we  can  say  with  truth  thai 
decision  as  to  their  novelty  being  made  by  those    it  is  a  volume  well  worth  buying  for  frequen^um. 
who  by  «ide  reading  ana  long  experience    are    —Virginia  Medico 
fully  competent  to  render  such  a  verdict.— 


HABERSHON,  S.  (>..    M.  />., 

i  Practice  of  Mrd.  at  Guii'<  Ifi'spita',  IvOndon. 

On  the  Diseases  of  the  Abdomen;    Comprising  those  of  tl      S  h,  and 

other  |  «arts  of  the  Alimentary  (anal,  CEsoph  m,  Intestines  and  Peritoneum.  > 

American   from  third  enlarged  and  revised   English  edition.     In  one  b  ctavo 

volume  of  554  pages,  with  illustrations,     (loth,  | 


PA  We  TREATISE  ON  THE  FUN<  HON  OF  DI- 
GESTION; its  in-orders  and  their  Treatment 
From  the  second  London  edition.    In  one 

volume  of  . 

('II A  M  BERS'  MANUAL  OF  Dl  F.T  \  M  >  H  Hi ;  I M  EN 
IN    HEALTH   AND  BICKNESa     In  on< 
some  octavo  volume  ■  :  75. 


BARLOWS  MANUAL  OF  THE  PRACTK 
MEDICINE.  With  additions  by  D.  F.  I 
M.  D.     1  vol.  8vo  ,  |p 

TODD'S  CLINICAL  LECTURES  ON  CERTAIN 
ACUTE  DISEASES,  In  one  octavo  volume  of 
390  pa _ 

HOLLAND'S  MEDICAL  NOTES  AND  REFLEC- 
TS INS,     1   vol.  -Hi,  pp.4  ,  ;;j.5o. 


18  Lea  Brothers  &  Co.'s  Publications — Throat,  Lungs,  Heart. 

COHEX,  J.  SOUS,  M.  JO., 

Lecturer  on  Laryngoscopy  and  Diseases  of  the  Throat  and  Chest  in  the  Jefferson  Medical  College. 

Diseases  of  the  Throat  and  Nasal  Passages.  A  Guide  to  the  Diagnosis  and 
Treatment  of  Affections  of  the  Pharynx,  (Esophagus,  Trachea,  Larynx  and  Nares.  Third 
edition,  thoroughly  revised  and  rewritten,  with  a  large  number  of  new  illustrations,  in 
one  very  handsome  octavo  volume.     Preparing. 


SEILEB,  CABL,  M.  D., 

Lecturer  on  Laryngoscopy  in  the  University  of  Pennsylvania. 

A  Handbook  of  Diagnosis  and  Treatment  of  Diseases  of  the  Throat, 
Nose  and  Naso-Pharynx.  Second  edition.  In  one  handsome  royal  12mo.  volume 
of  294  pages,  with  77  illustrations.     Cloth,  $1.75. 

It  is  one  of  the  best  of  the  practical  text-books  |  the  essentials  of  diagnosis  and  treatment  in  dis- 
on  this  subject  with  which  we  are  acquainted.  The  :  eases  of  the  throat  and  nose.  The  art  of  laryngos- 
present  edition  has  been  increased  in  size,  but  its  j  copy,  the  anatomy  of  the  throat  and  nose  and  the 
eminently  practical  character  has  been  main-  ,  pathology  of  the  mucous  membrane  are  discussed 
tained.  Many  new  illustrations  have  also  been  with  conciseness  and  ability.  The  work  is  pro- 
intro.!  .  e-reeord  sheet  has  been  added,    fusely  illustrated,  excels  in  many  essential  feat- 

and  there  are  a  valuable  bibliography  and  a  good  ares,  and  deserves  a  place  in  the  office  of  the 
index  of  the  whole.  For  any  one  who  wishes  to  practitioner  who  would  inform  himself  as  to  the 
make  himself  familiar  with  the  practical  manage-  nature,  diagnosis  and  treatment  of  a  class  of  dis- 
ment  of  eases  of  throat  and  nose  disease,  the  book  i  eases  almost  inseparable  from  general  medical 
will  be  found  of  great  value. — Xew  York  Medical  '  practice.  With  advanced  students  the  book  must 
Journal,  June  9, 1883.  be  very  popular  on  account  of  its  condensed  style. 

The  work  before  us  is  a  concise  handbook  upon  |  — Louisville  Medical  News,  June  26, 1883. 

BROWNIE,  LENNOX,  F.  B.  C.  S.,  Edin., 

Senior  Surgeon  to  the  Central  London  Throat  and  Ear  Hospital,  etc. 
The  Throat  and  its  Diseases.     Second  American  from  the  second  English  edi- 
tion, thoroughly  revised.     With  100  typical  illustrations  in  colors  and  50  wood  engravings, 
designed  and  executed  by  the  Author.     In  one  very  handsome  imperial  octavo  volume  of 
about  350  pages.     Preparing. 

FLINT,  AUSTIN,  31.  D., 

Professor  of  the  Principles  and  Practice  of  Medicine  in  Bellevue  Hospital  Medical  College,  N.  T. 

A  Manual  of  Auscultation  and  Percussion ;  Of  the  Physical  Diagnosis  of 
Diseases  of  the  Lungs  and  Heart,  and  of  Thoracic  Aneurism.  Third  edition.  In  one  hand- 
some royal  12mo.  volume  of  210  pages.     Cloth,  $1.63. 

It  is  safe  to  say  that  there  is  not  in  the  English  [  the  results  of  his  careful  study  and  ample  ex- 
language,  or  any  other,  the  equal  amount  of  clear,  !  perience  in  such  wise  that  the  young  will  find  it  the 
exact  ana  comprehensible  information  touching  |  best  source  of  instruction,  and  the  old  the  most 
the  physical  exploration  of  the  chest,  in  an  equal  pleasant  means  of  reviving  and  complementing 
number  of  words.  Professor  Flint's  language,  is  their  knowledge.  —  American  Practitioner,  June, 
precise  and  simple,  conveying  without  dubiety  [  1S83. 


BY  THE  SAME  AUTHOR. 

Physical  Exploration  of  the  Lungs  by  Means  of  Auscultation  and 
Percussion.  Three  lectures  delivered  before  the  Philadelphia  County  Medical  Society, 
1882-S3.     In  one  handsome  small  12mo.  volume  of  83  pages.     Cloth,  $1.00. 

A  Practical  Treatise  on  the  Physical  Exploration  of  the  Chest  and 
the  Diagnosis  of  Diseases  Affecting  the  Respiratory  Organs.  Second  and 
revised  edition.     In  one  handsome  octavo  volume  of  591  pages.     Cloth,  §4.50. 

Phthisis:  Its  Morbid  Anatomy,  Etiology,  Symptomatic  Events  and 
Complications,  Fatality  and  Prognosis,  Treatment  and  Physical  Diag- 
nosis ;  In  a  series  of  Clinical  Studies.  In  one  handsome  octavo  volume  of  442  cages. 
Cloth,  $3.50.  

A  Practical  Treatise  on  the  Diagnosis,  Pathology  and  Treatment  of 
Diseases  of  the  Heart.  Second  revised  and  enlarged  edition.  In  one  octavo  volume 
of  55D  pages,  with  a  plate.     Cloth,  $4. 


GBOSS,  S.  I).,  M.I).,  LL.D.,  D.C.L.  Oxon..  II.D.  Cantab. 

A  Practical  Treatise  on  Foreign  Bodies  in  the  Air-passages.    In  one 
octavo  volume  of  452  pages,  with  59  illustrations.     Cloth,  $2.75. 

FULLER  ON  DISEASES  OF  THE  LUNGS  AND  SMITH  ON  CONSUMPTION;  its  Early  and  Reme- 

AIi:                     -.  Their  Pathology,  Physical  Di-  '      diable  Stages.    1  vol.  8vo.,  pp.  253.    Cloth,  $2.25. 

agnosis,  Symptoms  and  Treatment.    From  the  LA  ROCHE  ON  PNEUMONIA.    1  vol.  8vo.  of  400 

ad   and    revised  English  edition.    In  one  pa^es     Cloth  S3  00 

octavo  volume  of  475  pages.    Cloth,  £3.50.  wiLUAMS  (^PULMONARY  CONSUMPTION; 

&LADEOIS  DIPHTHERIA;  its  Nature  and  Treat-  its  Nature,  Varieties  and  Treatment.     With  an 

ment,  with  an  account  of  the  History  of  its  Pre-  analysis  of  one  thousand  cases  to  exemplify  its 

valence  in  various  Countries.  Second  and  revised  duration.   In  one  8vo.  vol.  of  303  pp.  Cloth,  $2.50. 

edition.    In  one  12mo.  vol.,  pp.  158.    Cloth,  81.25.  J0NES' CLINICAL  OBSERVATIONS  ON  FUNC- 

WALSHE  ON  THE  DISEASES  OF  THE  HEART  TIONAL  NERVOUS  DISORDERS.  Second  Am- 

AND  GREAT  VESSELS.    Third  American  edi-  erican  edition.    In  one  handsome  octavo  volume 

tion.    In  1  vol.  8vo.,  416  pp.    Cloth,  83.00.  of  340  pages.    Cloth,  83.25. 


Lea  Brothers  &  Co.'s  Publications — Nerv.  and  Ment.  Dis.,  etc.     19 
MITCHELL,  S.  WEIR,  31.  I)., 

Physician  to  Orthopaedic  Hospital  and  the  Infirmary  for  Diseases  of  the  Nervous  System,  Phila.,  etc. 

Lectures  on  Diseases  of  the  Nervous  System;  Especially  in  Women. 
Second  edition.     In  one  12m  of  288  pages.     Cloth,  $1.75.     Just  ready. 


We  feel  sure  thai  the  new  edition  of  Dr.  Mitch 
ell'8  admirable  lectures  will  be  received  on  this 
side  of  the  Atlantic  with  more  than  ordinary  at- 
tention.    His  subject,  the  nervous  disorders  of 


women,  is  one  that  interests  every  practitioner, 
and  his  views  on  treatment  are  gradually  receiving 
general  acceptance. — London    1&  tes  and 

July  4, 1885. 


BOSS,  JAMES,  31.  D.,  F.R.  C.P.,  LL.  L>., 

Senior  Assistant  Physician  to  the  Manchester  Royal  Infirmary. 

A  Text-Book  on  Diseases  of  the  Nervous  System.   In  one  handsome 
octavo  volume  of  600  pages,  fully  illustrated.     Shortly. 


HAMILTON,  ALLAN  McLAJSE,  M.  H., 

Attending  Physician  at  the  Hospital  for  Epileptics  and  Paralytics,  BlackweWs  Island,  N.  Y. 
Nervous  Diseases  ;  Their  Description  and  Treatment.     Second  edition,  thoroughly 
revised  and  rewritten.    In  one  octavo  volume  of  598  pages,  with  72  illustrations.    Cloth,  $4. 

When  thefirstedition  of  this  good  book  appeared  characterized  this  book  as  the  best  of  its  kind  in 

we  gave  it  our  emphatic   endorsement,  and  the  any  language,  which  is  a  handsome  endorsement 

E  resent  edition  enhances  our  appreciation  of  the  from  an  exalted  source.  The  improvements  in  the 

ook  and  its  author  as  a  safe  guide  to  students  of  new  edition,  and  the  additions  to  it,  will  justify  its 

clinical  neurology.      One  of  the  best  and  most  purchase  even  by  those  who  possess  the  old. — 

critical  of  English  neurological  journals,  Brain,  has  i  Alienist  and  Neurologist,  April,  1882. 

TUKJE,  DANIEL  HACK,  M.  D., 

Joint  Authm  of  The  Manual  of  Psychological  Medicine,  etc. 

Illustrations  of  the  Influence  of  the  Mind  upon  the  Body  in  Health 
and  Disease.  Designed  to  elucidate  the  Action  of  the  Imagination.  New  edition. 
Thoroughly  revised  and  rewritten.  In  one  handsome  octavo  volume  of  467  pages,  with 
two  colored  plates.     Cloth,  $3.00. 

It  is  impossible  to  peruse  these  interesting  chap-  ;  method  of  interpretation.    Guided  by  an  enlight- 
ters  without  being  convinced  of  the  author's  per-    ened    deduction,    the    author  has   reclaimed  for 


feet  sincerity,  impartiality,  and  thorough  mental  |  science  a  most  interesting  domain  in  psychology, 
grasp.  Dr.  Tuke  has  exhibited  the  requisite  ;  previously  abandoned  to  charlatans  and  empirics, 
amount  of  scientific  address  on  all  occasions,  and  .  This  book,  well  conceived  and  well  written,  must 
the  more  intricate  the  phenomena  the  more  firmly  commend  itself  to  every  thoughtful  understand- 
has   he  adhered  to  a  physiological  and  rational  '  ing. — New  York  Medical  journal,  September  0,1884. 


CLOUSTON,  THOMAS  S.,  M.  D.,  F.  It.  C.  P.,  L.  R.  C.  S., 

Lecturer  on  Mental  Diseases  in  the  University  of  Edinburgh. 

Clinica? Lectures  on  Mental  Diseases.  With  an  Appendix,  containing  an 
Abstract  of  the  Statutes  of  the  United  States  and  of  the  Several  States  and  Territories  re- 
lating to  the  Custody  of  the  Insane.  By  Charles  F.  Folsom,  M.  D.,  Assistant  Professor 
of  -Mental  Diseases,  Medical  Department  of  Harvard  University.  In  one  handsome 
octavo  volume  of  541  pages,  illustrated  with  eight  lithographic  plates,  four  of  which 
are  beautifully  colored.     Cloth,  S4. 


The  practitioner  aa  well  as  the  student  will  ac- 
cept the  plain,  practical  teaching  of  the  author  as  a 
forward  step  in  the  literature  of  insanity.  It  is 
refreshing  to  find  a  physician  of  Dr.  Clouston's 
experience  and  high  reputation  giving  the  bed- 
side notes  upon  whirl,  his  experience  has  been 
founded  and  his  mature  judgment  established. 
Such  clinical  observations  cannot  but  be  useful  to 


the  general  practitioner  in  guiding  him  to  a  diag- 
■id  indicating  the  treatment,  especially  in 
many  obscure  and  doubtful  cases  of  mental  dis- 
ease. To  the  American  reader  Dr.  Folsom's  Ap- 
pendix adds  greatly  to  the  value  of  the  work,  and 
will  make  it  a  desirable  addition  to  even-  library. 
— Amen-  ogical  Journal,  July,  1884. 

'Dr.   Folsom's  Abstract  may  also  be  obtained  separately  in  one  octavo  volume  of 
Cloth,  $1.50. 

SAVAGE,  GEORGE  H.,  M.  D., 

hi  et  i  •  r  oi    1 1  Hospital,  1 1 

Insanity  and    Allied   Neuroses,    Practical   and   Clinical.     In  one  12mo.  vol- 
ume ot'  551  pages,  with  IS  typical  illustrations.     Cloth,  f 2.00.     Just  ready.     See  Series  of 
Clinical  Man  wah,  page  3. 
As  a  handbook,  a  Kuide  to  practitioners  and  atu-    common  •■rywhere  apparent.    We  re- 


dents,  the  book  fulfils  an  admirable  purpose.  The 
many  forms  of  insanity  are  described  with  char- 
acteristic clearness,  the  illustra  :e  care- 
fully selected,  and  as  regards  treatment,  sound 


it  l>r.  Savage  has  written  an  excellent 
manual  for  the  practitioner  and  student. — Am- 
i  riean  Journal  of  Insanity,  April,  1885. 


FLAYFAIR,  W.  S.,  31.   D.,  F.  R.  C.  P., 

The  Systematic  Treatment  of  Nerve  Prostration  and  Hysteria.    In 
one  handsome  small  V2mo.  volume  of  97  pages.     Cloth,  $1.00. 


Blandford  on  Insanity  and  its  Treatment:   Lectures  on  the  Treatment, 

Medical  and  Legal,  of  Insane  Patients.    In  one  very  handsome  octavo  volume. 


20  Lea  Brothers  &  Co.'s  Publications — Surgery. 


GROSS.   S.  D.,  31.  D.,  LL.  D.,  D.  C.  L.   Oxon.,  XI.  JD. 
Cantab,, 

Emeritus  Professor  of  Surgery  in  the  Jefferson  Medical  College  of  Philadelphia. 
A  System  of  Surgery :    Pathological,   Diagnostic,  Therapeutic  and   Operative. 
Sixth  edition,  thoroughly  revised  and  greatly  improved.     In  two  large  and  beautifully- 
printed  imperial  octavo  volumes  containing  2382  pages,  illustrated  by  1623  engravings. 

ugly  bound  in  leather,  raised  bands,  $15;  half  Russia,  raised  bands,  $16. 

Dr.  •  "  of  Surgery  has  long  been  the    material  has  been  introduced,  and  altogether  the 

Btandard  work  on  that  subject  for  students  and  distinguished  author  has  reason  to  be  satisfied 
practitioners.— -London  Lancet,  May  10,  1884  that  he  ha«  placed  the  work  fully  abreast  of  the 

The  work  as  a  whole  needs  no  commendation,  state  of  our  knowledge. — Med.  Retard,  Nov.  18, 1882. 
Hany years  ago  it  earned  for  itself  the  enviable  rep-  :  His  System  of  Surgery,  which,  since  its  first  edi- 
utati'on  of  the  leading  American  work  on  surgery,  '  tion  in  1859,  has  been  a  standard  work  in  this 
and  it  is  still  capable  of  maintaining  that  standard,  country  as  well  as  in  America,  in  "the  whole 
The  reason  for  this  need  only  be  mentioned  to  be  j  domain  of  Burgery,"  tells  how  earnest  and  labori- 
appreciated.  The  author  has  always  been  calm  ous  and  wise  a  surgeon  lie  was  how  thoroughly 
and  judicious  in  his  statements,  has  based  his  eon-  he  appreciated  the  work  done  by  men  in  other 
elusions  on  much  study  and  personal  experience,  countries,  and  how  much  he  contributed  to  pro- 
has  been  able  to  grasp  his  subject  in  its  entirety,  '  mote  the  science  and  practice  of  surgery  in  his 
and,  above  all,  has  conscientiously  adhered  to  j  own.  There  has  been  no  man  to  whom  America 
truth  and  fact,  weighing  the  evidence,  pro  and  j  is  so  much  indebted  in  this  respect  as  the  Nestor 
con,  accordingly.    A  considerable  amount  of  new  !  of  surgery. — British  Medical  Journal,  May  10, 1884. 


ASHHTJRST,  JOHN,  Jr.,  31.  D., 

Professor  of  Clinical  Surgery,  Univ.  of  Penna.,  Surgeon  to  the  Episcopal  Hospital,  Philadelphia. 

The  Principles  and  Practice  of  Surgery.  Fourth  edition,  enlarged  and 
revised.  In  one  large  and  handsome  octavo  volume  of  about  1100  pages,  with  about  575 
illustrations.     Shortly. 

GOULD,  A.  REARCE,  M.  S.,  31.  B.,  F.  R.  C.  8., 

stant  Surgeon  to  Middlesex  Hospital. 

Elements  of  Surgical  Diagnosis.    In  one  pocket-size  12mo.  volume  of  589 
pages.     Cloth,  $2.00.    \Tust  ready.        See  Students'  Series  of  Manuals,  page  3. 
The    student   and    practitioner    will    find  the  |  and  if  practitioners  would  devote  a  portion  of  their 

leisure  to  the  study  of  it,  they  would  receive 
immense  benefit  in  the  way  of  refreshing  their 
knowledge  and  bringing  it  up  to  the  present  state 
of  progress. — Cincinnati  Medical  News,  Jan.,  1885. 


principles  of  surgical  diagnosis  very  satisfactorily 
set  forth  with  all  unnecessary  verbiage  elimi- 
nated. Every  medical  student  attending  lectures 
should  have  a  copy  to  study  during  the  intervals, 


GIBNEY,  V.  R.,  M.  D., 

Surgeon  to  the  Orthopcedic  Hospital,  New  York,  etc. 
Orthopaedic  Surgery.    For  the  use  of  Practitioners  and  Students.    In  one  hand- 
some octavo  volume,  profusely  illustrated.     Preparing. 

ROBERTS,  JOHN  B.,  A.  31.,  M.  D., 

Lecturer  on  Anatomy  and  on  Operative  Surgery  at  the  Philadelphia  School  of  Anatomy. 

The  Principles  and  Practice  of  Surgery.  For  the  use  of  Students  and 
Practitioners  of  Medicine  and  Surgery.  In  one  very  handsome  octavo  volume  of  about  500 
pages,  with  many  illustrations.     Preparing. 

BELLAMY,  EDWARD,  F.  R.  C.  S., 

Surgeon  and  Lecturer  on  Surgery  at  Charing  Cross  Hospital,  London. 
Operative  Surgery.     Shortly.     See  Students'  Series  of  Manuals,  page  3. 


ST13ISON,  LEWIS  A.,  B.  A.,  31.  D., 

Prof,  of  Pathol.  Anat.  at  the  Univ.  of  the  City  of  Nexo  York,  Surgeon  and  Curator  to  Bellevue  Hosp. 

A  Manual  of  Operative  Surgery.  New  (second)  edition.  In  one  very  hand- 
some royal  12mo.  volume  of  about  500  pages,  with  about  350  illustrations.  Cloth,  $2.50. 
Shortly. 

A  notice  of  the  previous  edition  is  appended. 
This  volume  is  devoted  entirely  to  operative  sur- 1  every  student    should    possess    one.    This  work 
gery,  a                          I  to  fai  liliarize  the  student    does  away  with  the  necessity  of   pondering  over 
with  the  details  of  operations  and   the  different    larger  works  on  surgery  for  descriptions  of  opera- 
modes  oing  them.    The  work  is  hand-    tions.asii  pr nta  in  a  nutshell  what  is  wanted 

■omely  illustrated,  and  the  de  are  clear  |  by  >a   without   an    elaborate  search  to 

and  well-drawn.    It  is  a  clever  and  useful  volume;  |  find  it.— Maryland  Medical  Journal,  August,  1878. 


SARGENTONBA  urn  OTHER  OPERA- I  PIRRIE'8    PRINCIPLES    AND    PRACTICE  OF 

TION8  OF  MINOR  8URGERY.  New  edition,  I  SURGERY.  Edited  by  John  Nbill,  M.  D.  In 
withaCha  tlitary  surgery.    One  12mo.  |      one  8vo.  vol.  of  784  pp.  with  316  illus.    Cloth,  83.75. 

volumeof '888  pages,  with  187  cuts.    Cloth,  $1.75.    COOPER'S   LECTURES   ON  THE  PRINCIPLES 

MILLER'S  PRINCIPLES  OF  SURGERY.    Fourth  '      KyU  PRACTICE  OF  SURGERY.  Inone  8vo.  vol. 
American  from  the  third  Edinburgh  edition.     In  |      of767oa«ea      cloth    8''  <J0 
one  8vo.  vol.  of  638  pages,  with  340  illustrations.  I  '    a„„„„„„  T 

SKEY'S  OPERATIVE  St  RGEKA  .  In  one  vol.  8vo. 

MILLER'S  PRACTICE  OF  SURGERY      Fourth1      "'  rith  81  woodcuts.    Cloth,  $3.25. 

and  revis.-d  American  from  the  last  Edinburgh  GIBSON'S  INSTITUTES  AND  PRACTICE  OF 
edition.  In  one  large  8vo.  vol.  of  082  pages,  with  '  SURGERY.  Eighth  edition.  In  two  octavo  vola. 
K4  illustrations.    Cloth,  JB.75.  of  966  pages,  with  34  plates.     Leather  $6.59. 


Lea  Brothers  &  Co.'s  Publications — Surgery. 


21 


ERICHSEJY,  JOHJST  E.,  F.  R.  S.,  F.  R.  C.  S., 

Professor  of  Surgery  in  University  College,  London,  etc. 
The  Science  and  Art  of  Surgery ;  Being  a  Treatise  on  Surgical  Injuries,  Dis- 
eases and  Operations.     From  the  eighth  and  enlarged  English  edition.     In  two  large  and 
beautiful    octavo    volumes   of   2316    pages,    illustrated    with   984  engravings   on  wood. 
Cloth,  $9;  leather,  raised  bands,  §11 ;  half  Russia,  raised  hands,  $12.     Just  ready. 

After  the  profession  has  placed  its  approval  upon  much  to  he  said  in  the  way  of  comment  or  criti- 
awork  to  the  extent  of  purchasing  seven  editions,  eism.  That  it  still  holds  its  own  goes  without  say- 
it  does  not  need  to  lie  introduced.  Simultaneous  ing.  The  author  infuses  into  it  his  large  experi- 
with  t lie  appearance  of  this  edition  a  translation  enee  and  ripe  judgment.  Wedded  to  no  school, 
is  being  made  into  Italian  and  Spanish.  Thus  committed,  to  do  theory,  biassed  by  no  hob: 
this  favorite  text-book  on  surgery  holds  jt«  own  in  imparts  an  honest  personality  in  hi'^  observations, 
spite  of  numerous  rivals  at  the  end  of  thirty  years,  and  his  teachings  are  the  rulings  of  an  impartial 
It  is  a  grand  hook,  worthy  of  the  art  in  the  interest  judge.  Such  men  are  always  safe  guides,  and  their 
of  which  it  is  written. — Detroit  Lancet,  Jan.  10, 1885.  works  stand   the  tests  of  time  and   experience. 

After   being   before   the   profession    for  thirty  Such  an  author  is  Eriehsen,  and  such  a  work  is  his 

Hid  maintaining  during  that  period  a  re-  cord,  Feb.  21, 1885. 
putation  as  a  leading  work  on  surgery,  there  is  d 

BRYANT,  THOMAS,  F.  R.  C.  S., 

Surgeon  and  Lecturer  on  Surgery  at  Quy's  Hospital,  London. 
The  Practice  of  Surgery.     Fourth  American  from  the  fourth  and  revised  Eng- 
lish edition.     In  one  large  and  very  handsome  imperial  octavo  volume  of  1040  pages,  with 
727  illustrations.     Cloth,  $6.50;  leather,  $7.50 ;  half  .Russia,  $8.00.     Just  ready. 

The  treatise  takes  in  the  whole  field  of  surgery,       This  most  magnificent  work  upon  surgery  has 
that  of  the  eye,  the  ear,  the  female  organs,  ortho-    reached  a  fourth  edition  in  this  country,  showing 
peedi  -s,    venereal   diseases,  and  military  surgery,    * 
as  well  as  more  common  and  general  topics.    All 
of    these    are    treated   with    clearness    and   with 
sufficient   fulness  to  suit  all   practical   purposes. 
The  illustrations  are  numerous  and  well  printed. 
We  do  not  doubt  that  this  new  edition  will  con- 
tinue to  maintain  the  popularity  of  this  standard 
work. — Medical  and  Surgical  Reporter,  Feb.  14,  '85. 


the  high  appreciation  in  which  it  is  held  by  the 
American  profession.  It  comes  fresh  from  the 
pen  of  the  author.  That  it  is  the  very  best  work 
on  surgery  for  medical  students  "  we  think 
there  can  be  no  doubt.  The  author  seems  to  have 
tood  just  what  a  student  needs,  and  has 
prepared  t lie  work  accordingly. — Cincinnati  I 
News,  January,  1885. 


By  the  same  Author. 
Diseases  of  the  Breast.    In  one  ]2mo.  volume.   Preparing.   See  Series  of  Clinical 
Manuals,  page  3. 

BUTLIJY,  hejsry  t.,  f.  r.  c.  s., 

Assistant  Surgeon  to  St.  Bartholomew's  Hospital,  London. 

Diseases    of  the  Tongue.     In  one  12mo.  volume  of  456  pages,  with  8  colored 
plates  and  3  woodcuts.     Cloth,  $3.50.     Just  ready.     See  Serif*  of  Clinical  Manuals,  page  3. 

ESMARCH,  Hv.  FRIEDRICH, 

Professor  of  Surgery  at  the  University  of  Kid,  etc. 

Early  Aid  in  Injuries  and  Accidents.     Five  Ambulance  Lectures.    Trans- 
lated In-  li.    B.    II.  PRINCESS  ChmSTIAN.     In  one  handsome  small   12mo.  volume  of  109 
pages,  with  24  illustrations.     Cloth,  75  cents. 
The  course  <>f  instruction  is  divided  Into  five    the  methods  of  affording  first  treatment  in  cases 
The  first,  or  introductory    of  frost-bite,  of  drowning,  of  suffocation,  of  loss  of 


consciousness  and    of  poisoning  are  described; 
and  the  fifth  lecture  beaches  how  injured  p 
may  be  most  safely  and  easily  transported  to  their 
co  a  medical  man,  or  to  a  hospital.    The 
illustrations  in  the  hook  are  clear  andgood.- 


sections  or  lectui 

lecture,  gives  a  brief  account  of  the  structure  and 
organization  of  the  human  body,  illustrated  by 
clear,  -ititahle  diagrams.    The  second  teaches  how 

e  judicious  help  in  ordinary  injuries — contu- 

,  wounds,  hemorrhage  and  poisoned  wounds. 

third  treats  of  first  aid  in  eases  of  fracture    col  Times  and  Gazette,  Nov.  4, 1882 
and  of  dislocations,  In  sprains  and  in  burns.    Next, 

TREVES,  FREDERICK,  F.  J!.  C.  S.. 

.1  v-  on  to  and  Lecturer  on  Surgery  at  the  London  Hospital. 

Intestinal  Obstruction.    In  one  pocket-size  l2mo.  volume  of  522  pages,  with  60 


illustrations.  Limp  cloth,  blue  edges,  $2.00. 

page  3. 

indard  work  on  a  subject  that  has  not  been 
so  comprehensively  treated  by  any  contemporary 
i  i   w  liter,    lis  completeness  rendei 

review  difficult,  since  evi  deserves  mi- 


•<  of  Clinical  Manuals, 


author  in  a  few  paragraphs.  Intes- 
tinal Obstruction  is  a  work  that  will  prove  of 
equal  value  to  tioner, the  studei 

•j,  sur- 


nute  attention,  and  it  is  impossible  to  do  thorough    t  :  mo/,  Jan.  31, 


BALL,  CHARLES  B.,  M.  Ch.,  Hub.,  F.  R.  C.  S.  E., 

Hospital,  Dublin. 

Diseases  of  the  Rectum  and  Anus.    Jn  one  12mo.  volume  of  550  page*. 
Preparing.  i  of  Clinical  Manual.',  page  3. 


HRIITT,  ROBERT,  M.  R.  C.  S..  etc. 

The  Principles  and  Practice  of  Modern  Surgery.     From  the  eighth 
London  edition.     In  one  8vo.  volume  of  687  pages,  with  432  illus.     Cloth,  $4;  leather,  $5. 


22  Lea  Brothers  &  Co.'s  Publications — Surgery. 

HOLMES,  TIMOTHY,  31.  A., 

Surgeon  and  Lecturer  on  Surgery  at  St.  George's  Hospital,  London. 

A  System  of  Surgery ;  Theoretical  and  Practical.  EN  TREATISES  BY 
VAEIOUS  AUTHORS.  American  edition,  thoroughly  revised  and  re-edited 
by  John  II.  Packard,  M.  D.,  Surgeon  to  the  Episcopal  and  St.  Joseph's  Hospitals, 
Philadelphia,  assisted  by  a  corps  of  thirty-three  of  the  most  eminent  American  surgeons. 
In  three  large  and  very  handsome  imperial  octavo  volumes  containing  3137  double- 
columned  pages,  with  979  illustrations  on  wood  and  13  lithographic  plates,  beautifully 
colored.  Price  per  volume,  cloth,  $6.00 ;  leather,  £7.00 ;  half  Russia,  $7.50.  Per  set,  cloth, 
$18.00  ;  leather,  $21.00  ;  half  Russia,  $22.50.     Sold  only  by  subscription. 

Volume  I.  contains  General  Pathology,  Morbid  Processes,  Injuries  in  Gen- 
eral, Complications  of  Injuries  and  Injuries  of  Regions. 

Volume  II.  contains  Diseases  of  Organs  of  Special  Sense,  Circulatory  Sys- 
tem, Digestive  Tract  and  Genito-Urlnary  Organ>. 

Volume  III.  contains  Diseases  of  the  Respiratory  Organs,  Bones,  Joints  and 
Muscles.  Diseases  of  the  Nervous  System,  Gunshot  Wounds,  Operative  and 
Minor  Surgery,  and  Miscellaneous  Subjects  (including  an  essay  on  Hospitals). 

This  great  work,  issued  some  years  sin£e  in  England,  has  won  such  universal  confi- 
dence wherever  the  language  is  spoken  that  its  republication  here,  in  a  form  more 
thoroughly  adapted  to  the  wants  of  the  American  practitioner,  has  seemed  to  be  a  duty 
owing  to  the  profession.  To  accomplish  this,  each  article  has  been  placed  in  the  hands  of 
a  gentleman  specially  competent  to  treat  its  subject,  and  no  labor  has  been  spared  to  bring 
each  one  up  to  the  foremost  level  of  the  times,  and  to  adapt  it  thoroughly  to  the  practice 
of  the  country.  In  certain  cases  this  bus  rendered  necessary  the  substitution  of  an  entirely 
new  essay  for  the  original,  as  in  the  case  of  the  articles  on  Skin  Diseases,  on  Diseases  of 
the  Absorbent  System,  and  on  Anaesthetics,  in  the  use  of  which  American  practice  differs 
from  that  of  England.  The  same  careful  and  conscientious  revision  has  been  pursued 
throughout,  leading  to  an  increase  of  nearly  one-fourth  in  matter,  while  the  series  of 
illustrations  has-been  nearly  trebled,  and  the  whole  is  presented  as  a  complete  exponent 
of  British  and  American  Surgery,  adapted  to  the  daily  needs  of  the  working  practitioner. 

In  order  to  bring  it  within  the  reach  of  eveiy  member  of  the  profession,  the  five  vol- 
umes of  the  original  have  been  compressed  into  three  by  employing  a  double-columned 
royal  octavo  page,  and  in  this  improved  form  it  is  offered  at  less  than  one-half  the  price  of  the 
original.  It  is  printed  and  bound  to  match  in  every  detail  with  Reynolds'  System  of  Medi- 
cine. The  work  will  be  sold  by  subscription  only,  and  in  due  time  every  member  of  the 
profession  will  be  called  upon  and  offered  an  opportunity  to  subscribe. 

The  authors  of  the  original  English  edition  are  the  library  of  any  medical  man.  It  is  more  wieldly 
men  of  the  front  rank  in  England,  and  Dr.  Packard  and  more  useful  than  the  English  edition,  and  with 
has  been  fortunate  in  securing  as  his  American  its  companion  work — "Reynolds'  System  of  Medi- 
coadjutors  such  men  as  Bartholow,  Hyde,  Hunt,  cine" — will  well  represent  the  present  state  of  our 
Conner,  Stimson,  Morton,  Hodgen,  Jewell  and  science.  One  who  is  familiar  with  those  two  works 
their  colleagues.  As  a  whole,  the  work  will  be  will  be  fairly  well  furnished  head-wise  and  hand- 
solid  and  substantial,  and  a  valuable  addition  to  wise. — The  Medical  News,  Jan.  7, 1882. 


STIMSON  LEWIS  A.,  B.  A.,  M.  &., 

Professor  of  Pathological  Anatomy  at  the  University  of  the  City  of  New  York,  Surgeon  and  Curator 
to  BeUevue  Hospital,  Surgeon  to  the  Presbyterian  Hospital,  yew  York,  etc. 

A  Practical  Treatise  on  Fractures.    In  one  very  handsome  octavo  volume  of 
598  pages,  with  360  beautiful  illustrations.     Cloth,  §4.75  ;  leather,  $5.75. 

The  author  has  given  to  the  medical  profession  l  the   surgeon  in  full  practice. — If.  O.  Medical  and 

in  this  treatise  on  fractures  what  is  likelv  to  be-  Surgical  Journal,  March,  1883. 

come  a  standard  work  on  the  subject.  It  is  certainly  The  author  gives  j  Q  e)ear  ianguage  all  that  the 
not  surpassed  by  any  work  written  m  the  English,  practjcal  surgeon  need  know  of  the  science  of 
or,  for  that  matter,  any  other  language.  The  au-  fractures,  their  etiology,  symptoms,  processes  of 
thor  tells  us  in  a  short,  concise  and  comprehensive  uniou  an'd  treatment,  according  to  the  latest  de- 
manner,  all  that  is  known  about  his  subject.  There  velopments.  On  the  basis  of  mechanical  analysis 
us  nothing  scanty  or  superficial  about  it  as  in  most  the  author  accurately  and  clearly  explains  the 
other  treatises;  on  the  contrary,  everything  is  thor-  cimieai  features  of  fractures,  and  by  the  same 
ough.  The  chapters  on  repair  of  fractures  and  their  method  arrives  at  the  proper  diagnosis  snd  rational 
treatment  show  nun  not  only  to  be  a  profound  stu-  treatment  A  thorough  explanation  of  the  patho- 
dent,  but  likewise  a  practical  surgeon  and  patholo-  logk.al  anatomv  and6a  careful  description  of  the 
gist.  His  mode  of  treatment  of  the  different  fract-  v^rionii  methods  of  procedure  make  the  book  full 
uresis  eminently  sound  and  practical.  We  consider  of  vahle  for  e  przctitioneT.-Centralblatt  fur 
this  work  one  of  the  best  on  fractures  ;  and  it  will  chirurgie.  May  19, 1883. 
be  welcomed  not  only  as  a  textrbook,  but  also  by 


MARSH,  HOWARD,  F.  It.  C.  S., 

Senior  Assistant  Surgeon  to  and  Lecturer  on  Anatomy  at  St.  Bartholomew's  Hospital,  London. 
Diseases  of  the  Joints.    In  one  12mo.  volume.   Preparing.  See  Series  of  Clinical 
Manuals,  page  3. 

FICK,  T.  EICKEREJYG,  F.  It.  C.  8., 

Surgeon  to  and  Lecturer  on  Surgery  at  St.  George's  Hospital,  London. 
Fractures  and  Dislocations.     In  one  12mo.  volume.     Preparing.     See  Series 
of  Clinical  Manuals,  page  3. 


Lea  Brothers  &  Co.'s  Pubi0:ations — Frac.,  Disloc,  Ophthal.      23 
HAMILTON,  FRANK  H,  M.  D.,  LL.  D., 

Surgeon  to  Bellevue  Hospital,  Xew  York. 

A  Practical  Treatise  911  Fractures  and  Dislocations.  Seventh  edition, 
thoroughly  revised  and  much  improved.  In  one  very  handsome  octavo  volume  of  998 
pages,  with  379  illustrations.  Cloth,  So. 50:  leather,  $6.50;  very  handsome  half  Russia, 
open  hack,  $7.00.     Just  read;/. 

Hamilton's  great  experience  and  wide  acquaint-  cent  work,  and  especially  of  the  recorded  re- 
ance  with  the  literature  of  the  subject  have  enabled  searches  and  improvements  made  by  the  author 
him  to  complete  the  labors  of  Malgaigne  and  to  himself  and  his  countrymen. — British  Medical 
place   the   reader  in    possession   of   the   advances     Journal,  May  9,  1S85. 

made  during  thirty  years.  The  editions  have  fol-  |  With  its  first  appearance  in  1859,  this  work  took 
lowed  each  other  rapidly,  and  they  introduce  us  rank  among  the  classics  in  medical  literature, 
to  the  methods  of  practice,  often  so  wise,  of  his  and  has  ever  since  been  quoted  by  surgeons  the 
American  colleagues.  More  practical  than  Mai-  :  world  over  as  an  authority  upon  the  topics  of 
gaigne's  work,  it  will  serve  as  a  valuable  guide  to  which  it  treats.  The  surgeon,  if  one  can  be  found 
the  practitioner  in  the  numerous  and  embarrass-  who  does  not  already  know  the  work,  will  find  it 
ing  cases  which  come  under  his  observation. —  I  scientific,  forcible  and  scholarly  in  text,  exhaustive 
i  Generates  de  MSdecine,  Paris,  Nov.  1884.         in  detail,  and  ever  marked  by  a  spirit  of  wise  con- 

This  work,  which,  since  its  first    appearance    servatism. — Louisville  Medical  News,  Jan.  10, 1885. 
twenty-five   years  ago,    I  through  many.      For  a  quarter  of  a  century  the  author  has  been 

editions,  and  been  much  enlarged,  may  now  be  elaborating  and  perfecting  his  work,  so  that  it 
fairly  regarded  as  the  authority  of  refer-   now  stands  a<  the  best  ol  its  kind  in  any  lan- 

ence  on  the  subjects  of  fractures  and  dislocations,  gnage.  As  a  text-book  and  as  a  book  of  reference 
Each  successive  edition  has  been  rendered  of  and  guidance  for  practitioners  it  is  .-im ply  invalu- 
greater  value  through  the  addition  of  more  re-    able. — yew  Orleans  Med.  and Swg.JownCl, Nov.  1881. 


JTILER,  HENRY  E.,  F.  R.  C.  S., 

Senior  Ass' t  Surgeon, Royal  Westminster  Ophthalmic  Hasp. ;  late  Clinical  A*.: ( ,  London. 

A  Handbook  of  Ophthalmic  Science  and  Practice.  In  one  handsome 
octavo  volume  of  460  pages,  with  125  woodcuts,  27  colored  plates,  and  selections  from  the 
Test-types  of  Jae-.r  and  Snellen.     Cloth,  $4.50;  leather,  $5.50.     Just  ready. 

This  work  is  distinguished  by  the  great  num.-  and  typical  illustrations  of  all  important  eye 
ber  of  colored  plates  which  appear  in  it  for  illus-  affections,  placed  in  juxtaposition,  so  as  to  be 
trating  various  pathological  conditions.  They  are  grasped  at  a  glance.  Beyond  a  doubt  it  is  the 
very  beautiful  in  appearance,  and  have  been  best  illustrated  handbook  of  ophthalmic  science 
executed  with  great  care  a-  to  accuracy.  An  ex-  which  has  ever  appeared.  Then,  what  is  still 
aminatiou  of  the  work  shows  it  to  be  one  of  high  better,  these  illustrations  are  nearly  all  original. 
ling,  one  that  will  be  regarded  as  an  authority  We  have  examined  this  entire  work  with  great 
among  le  treatment  recom-    care,  and  it  the  commonly  accepted 

uch  as  the  author  has  learned  from  views  of  advanced  ophthalmologi-ts.  We  can  most 
actual  experience  to  be  the  best. — Cincinnati Medi-  heartily  commend  this  book  to  all  medical  stu- 
cal  Neu  dents,     practitioners    and     specialists. —  Detroit 

It  presents  to  the  student  concise  descriptions  :  Lancet,  Jan.  1885. 


WELLS,  J.  SOELBERG,  F.  R.  C.  S., 

of  Ophthalmology  in  King's  College  Hospital,  London,  etc. 
A  Treatise  on  Diseases  of  the  Eye.     Fourth  American  from  the  third  London 
edition.     Thoroughly  revised,  with  copious  additions,  by  Charles  S.  Bull,  M.D.,  Surgeon 
and  Pathologist  to  the  New  York  Eye  and  Ear  Infirmary.     In  one  large  octavo  volume  of 
'ages,  with  257  illustrations  on  wood,  six  colored  plates,  and  selections  from  the  Test- 
■-f  Jaeger  and  Snellen.     Cloth,  $5.00;  leather,  $6.00;  half  Eussia,  $6.50. 
The  present  edition  appears  in  less  than  three    shows  the  fidelity  and  thoroughness  with  which 
years  since  the  publication  of  the  last  American     the  editor  has  accomplished  his  part  of  the  work. 
edition,  and  yet,  from  the  numerous  recent  inves-    The  illustrations  throughout  are  good    This  edi- 
tigatione  that  have  been  made  in  this  branch  of    tion  can  be  recommended  to  all  as  a  complete 
ae.  many  changes  and  additions  have  been     treatise  on  diseases  of  the  eye,  than  which  proba- 
required  to  meet  the  present  scope  of  knowledge    bly  none  better  exists. — Medtcal  Record,  Aug.  18, '83. 
upon  this  subject.    A  critical  examination  at  once  | 


NETTLESHIF,  EDWARD,  F.  R.  C.  S., 

Ophf  ;.  and  Lect.  on  Ophth.  Surg,  at  St.  Thomas'  Hospital,  London. 

The  Student's  Guide  to  Diseases  of  the  Eye.  Second  edition.  With  a  chap- 
ter on  the  Detection  of  Color-Blindness,  by  William  Thomson,  M.  I).,  Ophthalmologist 
to  the  Jefferson  Medical  College.  In  one  royal  ll!ino.  volume  of  416  pages,  with  138 
illustrations.    (  I 

This  admirable  guide  bids  fair  to  become  the  j  and  well  chosen.    This  book,  within  the  short  corn- 
favorite  text-book  on  ophthalmic  surgery  with  stu-    pass  of  about 400  pages,  contains  a  lucid  exposition 
dents  and  general  practitioners.   It  bears  through-    of  the  modern  aspect  of  ophthalmic  science. — 
out  the  imprint  of  sound  judgment  combined  with     Medical  Record,  June  23,  1883. 
vast  experience.    The  illustrations  are  numerous  | 

BROWNE,  EDGAR  A., 

Surgeon  to  the  Liverpool  Eye  and  Ear  Infirmary  and  to  the  Dispensary  for  Skin  Diseases. 

How  to  Use  the  Ophthalmoscope.    Being  Elementary  Instructions  in  Oph- 
thalmoscopy, arranged  for  the  use  of  Students.     In  one  small  royal  12mo.  volume  of  116 
with  35  illustrations.     Cloth,  $1.00. 

LAW80N  ON  INJURIES  TO  THE  EYE,  ORBIT  j     titioners.    Second  edition.    In  one  octavo  vol- 
AND  EYELIDS:  Their  Immediate  and  Remote        ume  of  227  pages,  with  65  illust.    Cloth,  32.75. 
Effects.     8vO.,404pp.,92iUU8.     (loth,  $3.50.  .  CARTER'S  PRACTICAL.  TREATISE  ON  DISEAS- 

LAURENCE  AND   MOON'S   HANKY   BOOK  OF         E80FTHEEYE.    Edited  by  John  Greek,  M.D. 
OPHTHALMIC  SURGERY,  for  the  use  of  Prac-         In  one  handsome  octavo  volume. 


Lea  Brothers  &  Co.'s  Publication^— Otol.,  Urin.  l>is.,Dent. 


BURNETT,  CHARLES  H.,  A.  31.,  31.  !>., 

Prof essor  of  Otology  in  ■  Iphia  Polyclinic;  President  of  the  American  Otological  Society. 

The  Ear,  Its  Anatomy,  Physiology  and  Diseases.  A  Practical  Treatise 
for  the  use  of  Medical  Students  and  Practitioners.  New  (second)  edition.  In  one  handsome 
octavo  volume  of  580  pages,  with  107  illustrations.   Cloth,  $4.00;  leather,  $5.00.  Just  ready. 

We  note  with  pleasure  the  appearance  of  a  second  carried  out,  and  much  new  matter  added.  Dr. 
edition  of  thl  work.    When  it  first  came  !  Burnett's  work  must  be  regarded  ;i<  a  very  valua- 

out  it  was  accepted  by  the  profession  as  one  of  ble  contribution  to  aural  surgery,  not  only  on 
the  standard  works  on  modern  aural  Burgeryin  account  of  its  comprehensiveness,  but  because  it 
the  English  language;  andin  bis  second  edition  contains  the  results  of  the  careful  personal  observa- 
Dr.  Burnett  has  fully  maintained  hi*  reputation,  tion  and  experience  of  this  eminent  aural  surgeon. 
for  the  book  is  replete  with  valuable  information  |  —London  Lancet,  Feb.  21,  1885. 
and  suggestions.    The  revision  has  been  carefully  | 

FOLITZER,  ADAM, 

Imperial- Royal  Prof,  of  Aural  Therap.  in  the  Univ.  of  Vienna. 
A  Text-Book  Of  the  Ear  and  its  Diseases.    Translated,  at  the  Author's  re- 
quest, by  James  Patterson  Casselis,  M.  D.,  M.  R.  C.  S.     In  one  handsome  octavo  vol- 
ume of  800  pages,  with  257  original  illustrations.     Cloth,  $5.50. 

The  work  itself  we  do  not  hesitate  to  pronounce  section,  and  this  again  by  the  pathological  physi- 
the  best  upon  the  subject  of  aural  diseases  which  ,  ology,  an  arrangement  which  serves  to  keep  up  the 
has  ever  appeared,  systematic  without  being  too  interest  of  the  student  by  showing  the  direct  ap- 
ditfuse  on  obsolete  subjects,  and  eminently  prac-  i  plication  of  what  has  preceded  to  the  study  of  dis- 
tk'a!  in  everysense.  The  anatomical  descriptions  i  ease.  The  whole  work  can  be  recommended  as  a 
of  each  separate  division  of  the  ear  are  admirable,  reliable  guide  to  the  student,  and  an  efficient  aid 
and  profusely  illustrated  by  woodcuts.  They  are  !  to  the  practitioner  in  his  treatment. — Boston  Med- 
followed    immediately  by  the  physiology  of  the  ;  ical  and  Surgical  Journal,  June  7,  1883. 


ROBERTS,  WILLIA3I,  31.  L>., 

Lecturer  on  Medicine  in  the  Manchester  School  of  Medicine,  etc. 

A  Practical  Treatise  on  Urinary  and  Renal  Diseases,  including  Uri- 
nary Deposits.  Fourth  American  from  the  fourth  London  edition.  In  one  hand- 
some octavo  volume  of  609  pages,  with  81  illustrations.     Cloth,  $3.50.     Just  ready. 

The  peculiar  value  and  finish  of  the  book  are  j  directly  or  indirectly  to  the  diagnosis,  prognosis 
derived  from  its  resolute  maintenance  of  a  clinical  i  and  treatment  of  urinary  diseases,  and  possesses 
and  practical  character.  This  volume  is  an  un-  a  completeness  not  found  elsewhere  in  our  laa- 
rivalled  exposition  of  everything  which   relates  |  guage. — The  Medical  Chronicle,  July,  1885.    q» 


GROSS,  S.  TJ.,  31.  T>.,  LL.  TJ.,  TJ.  C.  L.,  etc. 

A  Practical  Treatise  on  the  Diseases,  Injuries  and  Malformations 
of  the  Urinary  Bladder,  the  Prostate  Gland  and  the  Urethra.  Third 
edition,  thoroughly  revised  by  Samuel  W.  Gross,  M.  D.,  Professor  of  the  Principles  of 
Surgery  and  of  Clinical  Surgery  in  the  Jefferson  Medical  College,  Philadelphia.  In  one 
octavo  volume  of  574  pages,  with  170  illustrations.     Cloth,  $4.50. 

MORRIS,  HE  WRY,  31.  B.,  F.  R.  C.  S., 

Sutgeon  to  and  Lecturer  on  Surgery  at  Middlesex  Hospital,  I^ondon. 

Surgical  Diseases  of  the  Kidney.  In  one  12mo.  volume.  Preparing.  See 
Series  of  Clinical  Manuals;  page  3. 


LUCAS,  CLEMENT,  M.  B.,  B.  S.,  F.  R.  C.  S., 

Senior  Assistant  Surgeon  to  Guy's  Hospital,  London. 

Diseases  of  the  Urethra.  In  one  12mo.  volume.  Preparing.  See  /Series 
of  Clinical  Manuals,  page  3. 

TH03IFSON,  SIR  JSENRY, 

Surgeon  and  Professor  of  Clinical  Surgery  to  University  College  Hospital,  London. 

Lectures  on  Diseases  of  the  Urinary  Organs.  Second  American  from  the 
third  English  edition.     In  one  8vo.  volume  of  203  pp.,  with  25  illustrations.     Cloth,  $2.25. 

By  the  Same  Author. 
On  the  Pathology  and  Treatment  of  Stricture  of  the  Urethra  and 
Urinary  Fistulse.     From  the  third  English  edition.     In  one  octavo  volume  of  359 
pages,  with  47   cuts  and  3  plates.     Cloth,  $3.50. 

COLE3IAN,  A.,  L.  R.  C.  P.,  F.  R.  C.  S.,  Exam.  L.  I>.  S., 

Senior  Dent.  Surg,  and  Lect.  on  Dent.  Surg,  at  St.  Bartholomew's  Hosp.  and  the  Dent.  Hasp.,  London. 

A  Manual  of  Dental  Surgery  and  Pathology.  Thoroughly  revised  and 
adapted  to  the  use  of  American  Students,  by  Thomas  C.  Stellwagen,  M.  A.,  M.  D., 
D.  I).  8.,  Prof,  of  Physiology  at  the  Philadelphia  Dental  College.  In  one  handsome  octavo 
volume  of  412  pages,  with  331  illustrations.     Cloth,  $3.25. 

BASHAM    ON    RENAL    DISEASES:   A   Clinical    I    one  12mo.  vol.  of  304  pages,  with  21  illustrations. 
Guide  to  their  Diagnosis  and    Treatment.    In    |    Cloth,  $2.00. 


Lea  Brothers  &  Co.'s  Publications — Venereal,  Impotence.  25 


BU3ISTEAI).  F.  J.,  and  TAYLOR,  B.  W., 

31.  !>.,  LL.  &.,  A.  M.,  31.  !>., 

Late  Professor  of  Venereal  Diseases  Surgeon  to  Charity  Hospital,  yen-  York,  Prof,  of 

at    th<  •  and  d  Skin  Diseases  in  tht   University  of 

Surgeons,  New  York,  etc.  f  the  Am.  Dertnatologieal  Asvn. 

The  Pathology  and  Treatment  of  Venereal  Diseases.  Including  the 
results  of  recent  Investigations  upon  the  subject.  Fifth  edition,  revised  and  largely  re- 
written, by  Dr.  Taylor.  In  one  large  and  handsome  octavo  volume  of  898  pages  with 
139  illustrations,  and  thirteen  chrome-lithographic  figures.  Cloth,  $4.75;  leather,  $5.75; 
very  handsome  half  Russia,  $6.25. 

It  is  a  splendid  record  of  honest  labor,  wide  ;  The  character  of  this  standard  work  is  so  well 
research,  just  comparison,  careful  scrutiny  an<l  known  that  it  would  be  superfluous  here  to  pass  in 
original  experience,  which  will  always  be  held  as  review  its  general  or  special  points  of  excellence, 
a  high  credit  to  American  medical  literature.  This  i  The  verdict  of  the  profession  has  been  passed;  it 
La  ool  only  the  best  work  in  the  English  language    has  been  accepted  a~  the  mi  gh  and  cora- 

npon  the  subjects  of  which  it  treats,  but  also  one  plete  exposition  of  the  pathology  and  treatment  of 
which  has  no  equa.  in  other  tongues  for  its  clear,  venereal  diseases  in  the  language.  Admirable  as  a 
comprehensive  and  practical  handling  of  its  !  model  of  clear  description,  an  exponent  of  sound 
themes. — American  Journal  of  the  Medical  Sciences,  j  pathological  doctrine,  and  a  guide  for  rational  and 
Jan,  1884.  successful  treatment,  it  is  an  ornament  to  the  medi- 

It  is  certainly  the  best  single  treatise  on  vene-  cal  literature  of  this  country.  The  additions  made 
real  in  our  own,  and  probably  the  best  in  any  Ian-  to  the  present  edition  are  eminently  judicious, 
guage. — Boston  Medical  and  Surgical  Journal,  April  from  the  standpoint  of  practical  utility. — Journal  of 
3,  1884.  i  Cutaneous  and  venereal  Diseases,  Jan.  1884. 


COBJSIL,  F., 

Professor  to  the  Faculty  of  Medicine  of  Paris,  and  Physician  to  the  Lourcine  Hosj 

Syphilis,  its  Morbid  Anatomy,  Diagnosis  and  Treatment.  Specially 
revised  by  the  Author,  and  translated  with  notes  and  additions  by  J.  Henry  C.  SlMES, 
M.  I).,  Demonstrator  of  Pathological  Histology  in  the  University  of  Pennsylvania,  and 
J.  William  White,  M.  D.,  Lecturer  on  Venereal  Diseases  and  Demonstrator  of  Surgery 
in  the  University  of  Pennsylvania.  In  one  handsome  octavo  volume  of  4G1  pages,  with 
84  very  beautiful  illustrations.     Cloth,  $3.75. 

The  anatomical  and  histological  characters  of  the  the  whole  volume  is  the  clinical  experience  of  the 
hard  and  sofl  sore  are  admirably  described.  The  author  or  the  wide  acquaintance  of  the  translators 
multiform  cutaneous  manifestations  of  the  disease  with  medical  literature  more  evident.  The  anat- 
are  dealt  with  histologically  in  a  masterly  way,  as  omy,  the  histology,  the  pathology  and  the  clinical 
we  should  indeed  expect  them  to  be,  and  the  features  of  syphilis  are  represented  in  this  work  in 
accompanying  illustrations  are  executed  carefully  their  best,  most  practical  and  most  instructive 
and  well.  The  various  nervous  I, "-ions  which  are  form,  and  no  one  will  rise  from  its  perusal  without 
the  recognized  outcome  of  the  syphilitic  dyscrasia  the  feeling  thai  his  grasp  of  the  wide  and  impor- 
are  treated  with  care  and  consideration.  Syphilitic  tant  subject  on  which  it  treats  is  a  stronger  and 
epilepsy,  paralysis,  cerebral  syphilis  and  locomotor  surer  one. —  The  London  Practitioner,  Jan.  1882. 
ataxia  are  subjects  full  of  interest ;  and  nowhere  iu  ; 


HTJTCHIJSSOX,  JOXATHAJV,  F.  B.  S.,  F.  B.  C.  S., 

Consulting  Surgeon  to  the  London  Hospital. 

Syphilis.    In  one  12mo.  volume.   Preparing.    See  Series  of  Clinical  Manuals,  page  3. 


GBOSS,  SA3IUEL  W.,  A.  31.,  31.  !>., 

Professor  of  the  Principles  of  Surgery  and  of  Clinical  Surgery  in  the  Jefferson  Medical  College. 

A  Practical  Treatise  on  Impotence,  Sterility,  and  Allied  Disorders 
of  the  Male  Sexual  Organs.  Second  edition,  thoroughly  revised.  In  one  very  hand- 
some octavo  volume  of  168  pages,  with  16  illustrations,     (loth,  $1.50. 

The  author  of  this  monograph  is  a  man  of  posi-  This  work  will  derive  value  from  the  high  stand- 
tive  convictions  and  vigorous  style.  This  isiusti-  ing  of  its  author,  aside  from  the  fact  of  its  passing 
fied  by  his  experience  and  by  his  study,  which  has  so  rapidly  into  its  second  edition.  This  is,  indeed, 
gone  hand  in  hand  with  his  experience.  In  regard  a  book  that  every  physician  will  be  glad  to  place 
to  the  various  organic  and  functional  disorders  of  in  his  library,  to  be  read  with  profit  to  himself, 
the  male  generative  apparatus,  he  has  had  ex-  and  with  incalculable  benefit  to  his  patient.  Be- 
ceptional  opportunities  for  observation,  and  his  Bides  the  subjects  embraced  in  the  title,  which  are 
book  shows  that  he  has  not  neglected  to  compare  treated  of  in  their  various  forms  and  degrees, 
his  own  views  with  those  of  other  authors.  The  spermatorrhoea  and  prostatorrhcea  are  also  fully 
result  is  a  work  which  can  be  safely  recommended  considered.  The  work  is  thoroughly  practical  in 
to  both  physicians  and  surgeons  as  a  guide  in  the  character,  and  will  be  especially  useful  to  the 
treatment  of  the  disturbances  it  refers  to.  It  is  general  practitioner. — Medical  kecord,  Aug.  is, 
the  best  treatise  on  the  subject  with  which  we  are  1883. 
acquainted. — The  Medical  News,  Sept.  l,  1883. 


CULLEBIEB,  A.,  &  BU3LSTEAF),  F.  J.,  3I.F).,  LL.JD., 

Surgeon  to  the  II6pital  du  Midi.  Late  Professor  at  Pi  nereal  Diseases  in  the  College  of  Physicians 

and  Surgeons,  Xc<r  Y.irk. 

An  Atlas  of  Venereal  Diseases.  Translated  and  edited  by  Freeman  .1.  Bum- 
stead,  M.  D.  In  one  imperial  lto.  volume  of  328  pages,  double-columns,  with  26  plates, 
containing  about  l~>u  figures,  beautifully  colored,  many  of  them  the  size  of  life.  Strongly 
bound  in  cloth,  $17.00.    A  specimen  of  the  plates  and  text  sent  by  mail,  on  receipt  of  25  cts. 

BILLON  8YPHILI8  AND  LOCAL  CONTAGIOUS    FORMS    OF     LOCAL     DISEASE    AFFECTING 
DISORDERS.  In  one  8vo  vol.  of  479  p.  Cloth,  $3.25.    PRINCIPALLY    THE    ORGANS    OF    GENERA- 
LEE'S   LECTURES  ON   SYPHILIS  AND  SOME    TION.     In  one  Svo.  vol.  of  -J4<.  pages.    Cloth,  $2.». 


26 


Lea  Brothers  &  Co.'s  Publications — Diseases  of  Skin. 


HYDE,  J.  JFEttirS,  A.  31.,  31.  &., 

Dermatology  and  Venereal  Diseases  in  Rush  Medical  College,  Chicago. 

A  Practical  Treatise  on  Diseases  of  the  Skin.  For  the  use  of  Students  and 
Practitioners.  In  one  handsome  octavo  volume  of  570  pages,  with  66  beautiful  and  elab- 
orate illustrations,    doth,  $4.25;  leather,  $5.25. 

The  author  has  given  the  student  and  practi-  ciao  in  active  practice.  In  dealing  with  these 
tioner  a  work  admirably  adapted  to  the  wants  of  questions  the  author  leaves  nothing  to  the  pre- 
eacli.  We  can  heartilv  commend  the  book  as  a  sumed  knowledge  of  the  reader,  but  enters  thor- 
valuable  addition  to  our  literature  and  a  reliable  oughly  into  the  most  minute  description,  bo  that 
guide  to  students  and  practitioners  in  their  studies  one  is  not  only  told  what  should  be  done  under 
and  practice.— Am.  Journ,   f  Med.  Set.,  July,  1883.       given  conditions  but  how  to  do  it  as  well.    It  is 

Especially  to  be  praised  are  the  practical  sug-  therefore  in  the  best  sense  "a  practical  treatise." 
gestiins  as' to  what  may  be  called  the  common-  i  That  it  is  comprehensive,  a  glance  at  the  index 
sense  treatment  of  eczema.  It  is  quite  impossible  will  show. — Maryland  Medical  Journal,  July  7, 1883, 
to  exaggerate  the  judiciousness  with  which  the  Professor  Hyde  has  long  been  known  as  one  of 
formula?  for  the  external  treatment  of  eczema  are  |  the  most  intelligent  and  enthusiastic  reprcsenta- 
selected,  and  what  is  of  equal  importance,  the  full  tives  of  dermatology  in  the  west.  His  numerous 
and  clear  instructions  for  their  use.— London  Medi-  contributions  to  the  literature  of  this  specialty 
«i/  Times  and  Gazette,  July  28,  1883.  have  gained  for  him  a  favorable  recognition  as  a 

The  work  of  I»r.  Hyde"  will  be  awarded  a  high  <  careful,  conscientious  and  original  observer.  The 
position.  The  student  of  medicine  will  find  it  remarkable  advances  made  in  our  knowledge  of 
peculiarly  adapted  to  his  wants.  Notwithstanding  diseases  of  the  skin,  especially  from  the  stand- 
the  extent  of  the  subject  to  which  it  is  devoted,  j  point  of  pathological  histology  and  improved 
vet  it  is  limited  to  a  single  and  not  very  large  vol-  I  methods  of  treatment,  necessitate  a  revision  of 
ume.  without  omitting  a  proper  discussion  of  the  the  older  textrbooks  at  short  intervals  in  order  to 
topics.  The  conciseness  of  the  volume,  and  the  |  bring  them  up  to  the  standard  demanded  by  the 
setting  forth  of  only  what  can  be  held  as  facts  will  march  of  science.  This  last  contribution  of  Dr. 
also  make  it  acceptable  to  general  practitioners.  '  Hyde  is  an  effort  in  this  direction.  He  has  at- 
— Cincinnati  Medical  News,  Feb.  1883.  '  tempted,  as  he  informs  us,  the  task  of  presenting 

The  aim  of  the  author  has  been  to  present  to  his  in  a  condensed  form  the  results  of  the  latest  ob- 
readers  a  work  not  only  expounding  the  most  :  servation  and  experience.  A  careful  examinatiod 
modern  conceptions  of  his  subject,  but  presenting  of  the  work  convinces  us  that  he  has  accomplishen 
what  is  of  standard  value.  He  has  more  especially  his  task  with  painstaking  fidelity  and  with  a  cred- 
devoted  its  pages  to  the  treatment  of  disease,  and  ;  itable  result. — Journal  of  Cutaneous  and  Venereal 
by  his  detailed  descriptions  of  therapeutic  meas-  i  Diseases,  June,  1883. 
ures  has  adapted  them  to  the  needs  of  the  physi- 


FOX,  T.,  M.D.,  F.R.  C.  P.,  mid  FOX,  T.  C,  B.A.,  M.R.  C.S., 

Physician  to  the  Department  for  Skin  Diseases,  Physician  for  Diseases  of  the  Skin  to  the 

University  College  Hospital,  London.  Westminster  Hospital,  London. 

An  Epitome  of  Skin  Diseases.  With  Formulae.  For  Students  and  Prac- 
titioners. Third  edition,  revised  and  enlarged.  In  one  very  handsome  12mo.  volume 
of  238  pages.     Cloth,  $1.25. 

The  third  edition  of  this  convenient  handbook  manual  to  lie  upon  the  table  for  instant  reference, 
calls  for  notice  owing  to  the  revision  and  expansion  Its  alphabetical  arrangement  is  suited  to  this  use, 
which  it  has  undergone.  The  arrangement  of  skin  I  for  all  one  has  to  know  is  the  name  of  the  disease, 
diseases  in  alphabetical  order,  which  is  the  method  and  here  are  its  description  and  the  appropriate 
of  classification  adopted  in  this  work,  becomes  a  treatment  at  hand  and  ready  for  instant  applica- 
positive  advantage  to  the  student.  The  book  is  tion.  The  present  edition  has  been  very  carefully 
one  which  we  can  strongly  recommend,  not  only  revised  and  a  number  of  new  diseases  are  de- 
to  students  but  also  to  practitioners  who  require  a  scribed,  while  most  of  the  recent  additions  to 
compendious  Bummary  of  the  present  state  of  dermal  therapeutics  find  mention,  and  the  formu- 
dermatology.— Br  Journal,  July  2, 1883.  ;  lary  at  the  end  of  the  book  has  been  considerably 

We  cordially  recommend  Fox's  Epitome  to  those    augmented.—  The  Medical  News,  December,  1883. 
whose  time  is  limited  and  who  wish   a   handy  | 

MORRIS,  3IALCOLM,  M.  &., 

Joint  Lecturer  on  Dermatology  at  St.  Mary's  Hospital  Medical  School,  London. 
Skin  Diseases ;  Including  their  Definitions,  Symptoms,  Diagnosis,  Prognosis,  Mor- 
bid Anatomy  and  Treatment.     A  Manual  for  Students  and  Practitioners.     In  one  12mo. 
volume  of  316  pages,  with  illustrations.     Cloth,  $1.75. 

To  physicians  who  would  like  to  know  something  ,  for  clearness  of  expression  and  methodical  ar- 
about  skin  diseases,  so  that  when  a  patient  pre-  rangement  is  better  adapted  to  promote  a  rational 
sents  himself  for  relief  they  can  make  a  correct    conception  of  dermatology — a  branch  confessedly 

difficult  and  perplexing  to  the  beginner. — St  Louis 
Courier  of  Medicine,  April,  1880. 

The  writer  has  certainly  given  in  a  small  compass 
a  large  amount  of  well-compiled  information,  and 
his  little  book  compares  favorably  with  any  other 
which  has  emanated  from  England,  while  in  many 
points  he  has  emancipated  himself  from  the  stub- 
bornly adhered  to  errors  of  others  of  his  country- 
men." There  is  certainly  excellent  material  in  the 
book  which  will  well  repay  perusal.— Boston  Med. 
and  Surg.  Journ.,  March,  1880. 


diagnosis  and  prescribe  a  rational  treatment,  we 
unhesitatingly  recommend  this  little  book  of  Dr. 
Morris.  The  affections  of  the  skin  are  described 
in  a  terse,  lucid  manner,  and  their  several  charac- 
teristics so  plainly  set  forth  that  diagnosis  will  be 
easy.  The  treatment  in  each  case  is  such  as  the 
experience  of  the  most  eminent  dermatologists  ad- 
vises.— Cincinnati  Medical  Wi  ».,  April,  1880. 

This  is  emphatically  a  learner's  book;  for  we 
can  safely  say,  that  in  t"he.  whole  range  of  medical 
literature  there  is  no  book  of  a  like  scope  which 


WILSOJV,  FRAS3IUS,  F.R.S. 

The  Student's  Book  of  Cutaneous  Medicine  and  Diseases  of  the  Skin. 
In  one  handsome  small  octavo  volume  of  535  pages.     Cloth,  $3.50. 

SILLIER,  THOMAS,  M.  &., 

Physician  to  the  Skin  Department  of  University  College,  London. 

Handbook  of  Skin  Diseases;  for  Students  and  Practitioners.     Second  Ameri- 
can edition.     In  one  12mo.  volume  of  353  pages,  with  plates.     Cloth,  $2.25. 


Lea  Brothers  &  Co.'s  Publications — Dis.  of  Women. 


27 


AN  AMERICAN  SYSTEM  OF  GYNAECOLOGY. 

A  System  of  Gynaecology,  in  Treatises  by  Various  Authors.  Edited 
by  Matthew  D.  Mann,  M.  D.,  Professor  of  Obstetrics  and  Gynaecology  in  the  Uni- 
versity of  Buffalo,  N.  Y.  In  two  handsome  octavo  volumes,  richly  illustrated.  In  active 
preparation. 

LIST  OF   CONTRIBUTORS. 


WILLIAM  H.  BAKER,  M.  D., 
FORDYCE  BARKER,  M.  D., 
ROBERT  BATTEY,  M.  D., 
SAMUEL  C.  BUSEY,  M.  D., 
HEXRY  F.  CAMPBELL,  M.  D., 
HENRY  C.  COE,  M.  D., 
E.  C.  DUDLEY,  M,  D, 
GEORGE  J.  ENGELMANX,  M.  D., 
HEXRY  F.  GARRIGUES,  M.  D., 
WILLIAM  GOODELL,  M.  !>., 
EGBERT  H.  GRANDIX,  M.  D., 
SAMUEL  W.  GROSS,  M.  D., 
JAMES  B.  HUNTER,  M.  D., 
A.  REEVES  JACKSON,  M.  D., 


EDWARD  W.  JENKS,  M.  D., 

WILLIAM  T.  LUSK,  M.  D., 

MATTHEW  D.  MAXX,  M.  D., 

ROBERT  B.  MAURY,  M.  D., 

PAUL  F.  MUNDE,  M.  D., 

C.  D.  PALMER,  31.  D., 

WILLIAM  M.  POLK,  M.  D., 

THADDEUS  A.  REAMY,  M.  D., 

A.  D.  ROCKWELL,  M.  D., 

ALEX.  J.  C.  SKEXE,  M.  D., 

R.  BTANSBURY  SUTTON,  A.  M.,  M.  D. 

T.  GAILLARD  THOMAS,  M.  D., 

ELI  VAX  DE  WALKER,  M.  D., 

W.  GILL  WYLIE,  M.  D. 


THOMAS,  T.  GAILLARD,  M.  &., 

Professor  of  Diseases  of  Women  in  the  College  of  Physicians  and  Surgeons,  N.  7. 

A  Practical  Treatise  on  the  Diseases  of  Women.  Fifth  edition,  thoroughly 
revised  and  rewritten.  In  one  large  and  handsome  octavo  volume  of  810  pages,  with  266 
illustrations.  Cloth,  $5.00 ;  leather,  $6.00 ;  very  handsome  half  Russia,  raised  bands,  $6.50. 
The  words  which  follow  "  fifth  edition"  are  in  vious  one.  As  a  book  of  reference  for  the  busy 
this  ease  no  mere  formal  announcement.  The  practitioner  it  is  unequalled. — Boston  Medical  any 
alterations  and  additions  which  have  been  made  are    .S  •  ',  April  7, 1880. 

both  numerous  and  important.  The  attraction  It  has  I teen  enlarged  and  carefully  revised.  It  is 
and  the  permanent  character  of  this  book  lie  in  a  condensed  encyclopaedia  of  gynaecological  medi- 
the  clearness  and  truth  of  the  clinical  descriptions  ,  cine.  The  style  of  arrangement,  the  masterly 
of  diseases;  the  fertility  of  the  author  in  thera-  manner  in  which  each  subject  is  treated,  and  the 
peutic  resources  and  the  fulness  with  which  the  honest  convictions  derived  from  probably  the 
details  of  treatment  are  described;  the  definite  largest  clinical  experience  in  that  specialty  of  any 
character  of  the  teaching;  and  last,  but  not  least,  in  this  country,  all  serve  to  commend  it  in  the 
the  evident  candor  which  pervades  it.  We  would  highest  terms  to  the  practitioner. — Nashville  jour. 
also  particularize  the  fulness  with  which  the  his-    of  Med.  and  Surg.,  Jan.  1881. 

tory  of  the  subject  is  gone  into,  which  makes  the  That  the  previous  editions  of  the  treatise  of  Dr. 
book  additionally  interesting  and  gives  it  value  as  Thomas  were  thought  worthy  of  translation  into 
awork  of  reference.— London   Medical   Times  and    German,  French,  Italian  and  Spanish,  is  enough 


to  give  it  the  stamp  of  genuine  merit.  At  home  it 
de  its  way  into  the  library  of  ever3T  obstet- 
rician and  gynaecologist  as  asafe  guide  to  practice. 
No  small  number  of  additions  have  been  made  to 
the  present  edition  to  make  it  correspond  to  re- 

Pacific  Metiical 


Gazette,  July  30,  1881. 

The  determination  of  the  author  to  keep  his 
book  foremost  in  the  rank  of  works  on  gynaecology 
is  most  gratifying.  Recognizing  the  fact  that  this 
can  only  be  accomplished  by  frequent  and  thor- 
ough revision,  he  has  spared  no  pains  to  make  the  cent'improvements  in  treatment. 
t  edition  more  desirable  even  than  the  pre-    an'i  Surgical  Journal,  Jan.  1881. 

EHIS,  ARTHUR  W..  M.  D.,  Lond.,  F.R.  C.JP.,  31. R.  C.S., 

' .  Obstetric  Physician  to  Middlesex  Hospital,  late  Physician  to  British  Lying-in  Hospital. 
The  Diseases  of  Women.     Including   their   Pathology,  Causation,  Symptoms, 
Diagnosis  and  Treatment.     A  Manual  for  Students  and  Practitioners.     In  one  handsome 
volume  of  576  pages,  with  148  illustrations.     Cloth,  $3.00;  leather,  $4.00. 
It  is  a  pleasure  to  read  a  book  so  thoroughly        The  greatest  pains  have  been  taken  with  the 
good  a«  this  one.    The  special  qualities  which  are    sections  relating  to  treatment.    A  liberal  selection 
conspicuous  are    thoroughness   in    covering    the    of  remei  en  for  each  morbid  condition, 

whole  ground,  clearness  of  description  and  con-  the  strength,  mode  of  application  and  other  details 
ciseness  of  statement.  Another  marked  feature  of  being  fully  explained.  The  descriptions  of  gyna> 
the  book  is  the  attention  paid  to  the  details  of  cofogical  manipulations  and  operations  are  full, 
many  minor  surgical  operations  and  procedures,  clear  and  practical.  Much  care  has  also  been  be- 
as,  for  instance,  the  use  of  tents,  application  of  stowed  on  the  parte  of  the  book  which  deal  with 
leeches,  and  use  of  hot  water  injections.  These  diagnosis— we  note  especially  the  pages  dealing 
are  among  the  more  common  methods  of  treat-  with  the  differentiation,  one  from  another,  of  the 
ment,  and  yet  very  little  is  said  about  them  I   kinds  of  abdominal  tumors.    The  prac- 

many  of  the  text-books.  The  book  is  one  to  be  i  titioner  will  therefore  find  in  this  book  the  kind 
warmly  recommended  especially  to  students  and  of  knowledge  he  most  needs  in  his  daily  work,  and 
general  practitioners,  who  need  a  concise  but  com-  he  will  be  ]  leased  with  the  clearness  and  fulness 
plete  rtsumt  of  tin  t.    Specialists,  too,    of  the  informaiiou  there  given.—  The  Practt 

will  find  many  useful  hints  in  its  pages.— Boston    Feb.  1882. 
Med.  and  Surg.  Journ.,  March  2, 1882. 


BARNES,  ROBERT,  M.  D.,  E.  R.  C.  I*., 

Obstetric  Physician  to  St.  Thomas'  Hospital,  London,  etc. 

A  Clinical  Exposition  of  the  Medical  and  Surgical  Diseases  of  Women. 
In  one  handsome  octavo  volume,  with  numerous  illustrations.     New  edition.     Preparing. 

WEST,  CHARLES,  M.  I). 

Lectures  on  the  Diseases  of  Women.     Third  American  from  the  third  Lon- 
don edition.     In  one  octavo  volume  of  543  pages.     Cloth,  $3.75 ;  leather,  $4.75. 


Lea  Brothers  &  Co.'s  Publications — Dis.  of  Women,  Midwty. 
EMMET,  THOMAS  ADDIS,  M.  D.,  LL.  D., 

the  Woman's  Hospital,  Xeic  York,  etc. 

The  Principles  and  Practice  of  Gynaecology ;  For  the  use  of  Students  and 
Practitioners  of  Medicine.  New  |  third)  edition,  thoroughly  revised.  In  one  large  and  vrery 
handsome  octavo  volume  of  B80  pages,  with  160  illustrations.     Cloth,  $5;   leather,  $6. 

kre  in  doabt  whether  to    congratulate  the  The  time  has  passed  when  Emi 

author  more  than  the  profession  upon  the  appear-  was  to  be  regarded  as  a  book  for  a  single  country 

ance  of  the  third  edition  of  this  well-known  work,  or  for  a  single  generation.    It  has  always  been  his 

lying,  as  it  does,  the  life-long  experience  of  aim  to  popularize  gynecology,  to  bring  it  within 

one  «                         ouously  distinguished  himself  easy  reach  of  the  general  practitioner.    The  orig- 

as  a  bold  8                      il  operator,  and  who  has  inality  of  the  ideas,  aside  from  the   perfect  con- 

ition   to  the  specialty,  we  fidence  which  we  feel  in  the  author's  statements, 

feel  sure  the  profession  will  not  fail  to  appreciate  compels   our  admiration   and   respect.     We   may 

the  privilege  thus  offered  them  of  perusing  the  well  take  an  honest  pride  in  Dr.  Emmet's  work 

views  and  practice  of  the  author.    His  earnestness  and  feel  that  his  book  can  hold  its  own  against  the 

of  purpose  and  conscientiousness    are   manifest,  criticism  of  two  continents.    It  represents  all  that 

only  his  individual   experience  but  is  most  earnest  and  most  thoughtful  in  American 

endeavors  to  represent  the  actual  state  of  gynie-  gynaecology.      Emmet's    work    will    continue    to 

-  cal   science  and  art. — British  Medical  Jour-  reflect  the  individuality,  the  sterling  integrity  and 

nil,  May  16,  I  the  kindly  heart  of  itshonored  author  long  after 

it  or  tittle  of  the  high  praise  bestowed  upon  smaller  books    have    been    forgotten. — American 

the  first  edition  is  abated.     It   is  still  a  book  of  Journal  of  Obstetrics,  May \  1885 

marked  personality,  one  based  upon  large  clinical  Any  work    on    gynaecology    by    Emmet    must 

experience,    containing    large  and   valuable    ad-  always  have  especial  interest  and  value.    He  has 

ditions  to  our  knowledge,  evidently  written  not  for  many  years*  been  an  exceedingly  busy  prac- 

only  with  honesty  of  purpose,  but  with  a  conscien-  titioner  in  this  department.    Few  men  have  had 

tious  sense  of  responsibility,  and  a  book  that  is  at  his  experience    an  i  opportunities.      Asa  guide 

once  a  credit  to  its  author  and  to  American  med-  either  for  the  general  practitioner  or  specialist. 

ical  literature.   We  repeat  that  it  is  a  book  to  be  it  is  second  to  none  other.      No  one  can  read 

I.   and  one  that  is  indispensable  to  every  Emmet  without  pleasure,  instruction  and  profit. 

giving  any  attention  to  gynaecology. —  — Cincinnati  Lancet  and  Clinic,  Jan  31,  1885. 
American  Jom                                           s,  April,  1885.  | 

DTJXCAX,  J.  MATTHEWS,  3I.D.,  LL.  D.,  F.  R.  S.  E.,  etc. 

Clinical  Lectures  on  the  Diseases  of  Women ;  Delivered  in  Saint  Bar- 
tholomew's Hospital.     In  one  handsome  octavo  volume  of  175  pages.     Cloth,  $1.50. 

They  are  in  every  way  worthy  of  their  author  ;  stamp  of  individuality  that,  if  widely  read,  as  they 

indeed,  we  look  upon   them   as  among  the   most  certainly  deserve  to  be,  they  cannot  fail  to  exert  a 

valuable  of  his  contributions.    They  are  all  upon  wholesome  restraint   upon   the   undue  eagerness 

matters  of  great  interest  to  the  general  practitioner,  with    which   many  young   physicians   seem   bent 

Some  of  them  deal  with  subjects  that  are  not,  as  a  upon  following  the  wild  teachings  which  so  infest 

rule,  adequately  handled  in  the  text-books;  others  the  gynaecology  of  the  present  day. — N.  Y.  Medical 

of  them,  while  bearing  upon  topics  that  are  usually  Journal,  March",  1880. 
treated  of  at  length  in  such  works,  yet  bear  such  a  ] 

MAY,   CHARLES  H.,  M.   D. 

Latt  i '  Yerk. 

A  Manual  Of  the  Diseases  of  Women,  Containing  a  concise  and  systematic 
exposition  of  theory  and  practice.     In  one  12mo.  volume  of  about  350  pages.     In  prwa. 

HODGE,  HUGH  L.,  31.  D., 

Emeritus  Professor  of  Obstetrics,  etc.,  in  the  University  of  Pennsylvania. 
On  Diseases  Peculiar  to  Women;  Including  Displacements  of  the    Uterus. 
:id  edition,  revised  and  enlarged.     In  one  beautifully  printed  octavo  volume  of  519 

with  original  illustrations.     Cloth,  $4.50. 

By  the  Same  Author. 

The  Principles  and  Practice  of  Obstetrics.  Illustrated  with  large  litho- 
graphic plates  containing  159  figures  from  original  photographs,  and  with  numerous  wood- 
cuts. In  one  large  quarto  volume  of  5-12  double-columned  pages.  Strongly  bound  in 
cloth,  $14.00. 

*  *  *  Specimens  of  the  plates  and  letter-press  will  be  forwarded  to  any  address,  free  by 
mail,  on  receipt  of  six  cents  in  postage  stamps. 

RA3ISBOTHA31,  ERAXCIS  H.,  31.  D. 

The  Principles  and  Practice  of  Obstetric  Medicine  and  Surgery; 

In  reference  to  the  Process  of  Parturition.  A  new  and  enlarged  edition,  thoroughly  revised 
by  the  Author.  With  additions  by  W.  V.  Keatewg,  M.  I>..  Professor  of  Obstetrics,  etc., 
in  the  Jefferson   Medical   I  Philadelphia.     In  one  large  and   handsome  imperial 

octavo  volume  of  040  pages,  with  <i4  full-page  plates  and  43  woodcuts  in  the  text,  contain- 
ing in  all  nearly  200  beautiful  figures.     Strongly  bound  in  leather,  with  raised  bands,  $7. 

ASHWELL'S  PRACTICAL  TREATISE  ON  THE  i      AND  OTHER  DISEASES  PECULIAR  TO  WO- 

DI8EAS    -    PECULIAR    TO    WOMEN.     Third        MEN.     In  one  8vo.  vol.  of  464  pages.    CIoth,S2.50. 

Am  a    the  third   and  revised  London     MEIGS  ON  THE  NATURE.SIGNS  AND  TREAT- 

edition.     In  one  8to.  vol..  pp.  520.    Cloth.  $3.50  MENT  OF  CHILDBED  FEVER.    In  one  8vo. 

RCHILL   ON    THE    PUERPERAL   FEVER        volume  of  346  pages.     Cloth,  $2.00. 


Lea  Brothers  &  Co.'s  Publications — Midwifery.  29 

PLAYFAIR,  W.  8.9  31.  H.,  F.  R.  C.  P., 

Professor  of  Obstetric  Medicine  in  King's  College,  London,  etc. 

A  Treatise  on  the  Science  and  Practice  of  Midwifery.  New  (fourth) 
American,  from  the  fifth  English  edition.  Edited,  with  additions,  by  Robert  P.  Har- 
ris, M.  D.  In  one  handsome  octavo  volume  of  604  pages,  with  3  plates  and  201  engrav- 
ings    Cloth,  $4  ;  leather,  $5 ;  half  Russia,  $5.50.     Just  ready. 


This  excellent  work  needs  no  commendation. 
For  many  years  it  has  maintained  a  deservedly 
high  ii  putation  among  teachers  as  a  text  book, 
and  in  the  profession  as  a  guide  to  t he  practical 
experiences  which  attend  the  obstetrician.  The 
present  edition,  under  the  supervision  of  Dr.  Har- 
ris, has  been  carefully  revised,  and  ninny  portions 
rewriten,  ami  the  whole  work  has  been  adapted  to 
the  wants  and  circumstances  of  this  continent. — 
i  al  Journal,  Aug.  1885.    q, 

Ed  the  short  time  that  this  excellent  and  highly 
esteemed  work  has  been  before  the  profea 


has  reached  a  fourth  edition  in  this  country  and  a 
fifth  one  in  England.  This  fact  alone  speaks  in 
high  praise  of  it,  and  it  seems  to  us  that  scarcely 
more  need  be  said  of  it  in  the  way  of  endorsement 
of  its  value.  Asa  text  book  for  students  and  for 
the  uses  of  the  general  practitioner  there  is  no 
work  011  obstetrics  superior  to  the  work  of  Dr. 
PI  ay  fair.  Its  teachings  are  practical,  written  in 
plain  language,  and  allbrd  a  correct  understanding 
of  the  art  of  midwifery.  No  one  can  be  disap- 
pointed in  it. — Cincinnati  Medical  News,  June,  lssi. 


BARNES,  ROBERT,  31.  H.,   and    FANCOURT,   31.  JD., 

Phi/s.  to  the  General  Lying-in  Hosp.,  Land.  Obstetric  Phys.  to  St.  Thomas'  Hosp.,  Lond. 

A  System  of  Obstetric  Medicine  and  Surgery,  Theoretical  and  Clin- 
ical. For  the  Student  and  the  Practitioner.  The  Section  on  Embryology  contributed  hy 
Prof.  Milnes  Marshall.  In  one  handsome  octavo  volume  of  about  1000  pages,  profusely 
illustrated.    Cloth,  $5;  leather,  $6.       In  a  few  days. 

BARKER,  FORDKE,  aTm.,  M.  D.,  ZL.  D.  Edin., 

Clinical  Professor  of  Midwifery  and  the  Diseases  of  Women  in  the  Bellevue  Hospital  Medical  Oollegs, 
New  York,  Honorary  Fellow  of  the  Obstetrical  Societies  of  London  and  Edinburgh,  etc.,  etc. 

Obstetrical  and  Clinical  Essays.    In  one  handsome  12mo.  volume  of  about 

300  pages.     Preparing. 

KING,  A.  F.  A.,  31.  L>„ 

Professor  of  Obstetrics  and  Diseases  of  Women  m  the  Medical  Department  of  the  Columbian  Univer- 
siti/,  Washington,  !>.  C,  and  in  the  University  of  Vermont,  etc. 

A  Manual  of  Obstetrics.  Second  edition.  In  one  7ery  handsome  12mo.  volum« 
of  331  pages,  with  59  illustrations.     Cloth,  $2.00. 

Itmu.-r  be  acknowledged  that  this  is  just  what  !  densed  style  of  composition,  the  writer  has  pre- 
it  pretends  to  be— a  sound  guide,  a  portable  epit-    sented  a  great  deal  of  what  it  is  well  that  every 
a  work  in  which  oi  matter    obstetrician  should  know  and  be  ready  to  practice 


has  been  presented,  leaving  out  all  padding  and 
chaff,  and  one  in  which  tin-  student  will  find  pure 
«  heal  i   i  nutriment  —  .v. 1 

ical  ami  Surgical  Journal,  May,  l*v !. 
In  a  series  of  short  paragraphs  and  by  a  Con- 


or prescribe.    The  fact  that  the  d<  n  and  for  the 

has  been  such  as  to  exhaust  the  first 
edition  in  a  little  over  a  year  and  a  half  speaks 
well  for  its  popularity. — American  Journal  of  the 
M.  du  "/  Scii  nr,st  April,  I 


LANHIS,  HENRY  G.9  A.  31.,  31.  D., 

i  in  Starling  Medical  College,  Columbus,  O. 

The  Management  of  Labor.      In  one  handsome  12mo.  volume  of  about  300 
with  30  illustrations.    Sho 

BARNES,  FANCOURT,  31.  I)., 

Obstetric  Physician  to  St.  Thomas'  Hospital,  London. 

A  Manual  of  Midwifery  for  Midwives  and  Medical  Students.  In  one 
royal  12mo.  volume  of  197  pages,  with  50  illustrations.     Cloth,  $1.25. 

PARVIN,  THEOPHILUS,  31.  D.,  LL.  J).. 

Professor  of  ObsU  tries  and  the  Diseases  of  Women  and  Childri  n  in  the  Jefferson  Medical  College. 
A  Treatise  on  Midwifery.     In  one  very  handsome  octavo  volume  of  about  550 
pages,  with  numerous  illustrations.     In  press. 

PARRY,  JOHN  S.,  31.  JD.,     ~ 

'  ician  to  Ho  ,  i  Hospital,  Vice-President  of  the  Obstet.  Society  of  Philadelphia, 

Extra- Uterine  Pregnancy :  Its  Clinical  History,  Diagnosis,  Prognosis  and 
Treatment.     In  one  handsome  octavo  volume  oi'"J7-J  pages.     Cloth,  $2.50. 

TANNER,  TH03IAS  HAWKES,  M.  2>. 

On  the  Signs  and  Diseases  of  Pregnancy.     First  American  from  the 
English  edition.    <  Ictavo,  490  pages,  with  4  colored  plates  and  16  woodcuts.    Cloth,  $4.25. 

WJNCKEL,  F. 

A  Complete  Treatise  on  the  Pathology  and  Treatment  of  Childbed, 
For  Students  and  Practitioners.  Translated,  with  the  consent  of  the  Author,  from  the 
second  German  edition,  by  J.  R.  Chadwick,  M.  D.     Octavo  484  pages.     <  ''oth,  $4.00. 


30 


Lea  Brothers  &  Co.'s  Publications — Midwfy.,  Dis.  Childn. 


LEISHMsLF,  WILLIAM,  31.  !>., 

Regius  Professor  of  Midwifery  in  the  University  of  Glasgow,  etc. 

A  System  of  Midwifery,  Including  the  Diseases  of  Pregnancy  and  the 
Puerperal  State.     Third  American  edition,  revised  by  the  Author,  with  additions  by 

John  b.  Parry,  M.  D.,  Obstetrician  to  the  Philadelphia  Hospital,  etc.     In  one  large  and 
very  handsome  octavo  volume  of  740  pages,  -with  205  illustrations.     Cloth,  $4.50 ;  leather, 
$5.50 ;  very  handsome  half  Russia,  raised  bands,  $6.00. 
The  author  is  broad  in  his  teachings,  and  dis-  j  preparation  of  the  present  edition  the  author  has 


cusses  briefly  the  comparative  anatomy  of  the  pel- 
vis and  the  mobility  of  the  pelvic  articulations. 
The  second  chapter  is  devoted  especially  to 
the  siudy  of  the  pelvis,  while  in  the  third  the 
female  organs  of  generation  are  introduced. 
The  structure  and  development  of  the  ovum  are 
admirably  described.  Then  follow  chapters  upon 
the  various  subjects  embraced  in  the  study  of  mid- 
wifery. The  descriptions  throughout  the  work  are 
plain  and  pleasing.  It  is  sufficient  to  state  that  in 
this,  the  last  edition  of  this  well-known  work,  every 
recent  advancement  in  this  field  has  been  brought 
forward. — Physician  and  Surgeon,  Jan.  1880. 

We  gladly  welcome  the  new  edition  of  this  ex- 
cellent text-book  of  midwifery.  The  former  edi- 
tions have  been  most  favorably  received  by  the 
profession  on  both  sides  of  the  Atlantic.    In  the 


made  such  alterations  as  the  progress  of  obstetri- 
cal science  seems  to  require,  and  we  cannot  but 
admire  the  ability  with  which  the  task  has  been 
performed.  We  "consider  it  an  admirable  text- 
book for  students  during  their  attendance  upon 
lectures,  and  have  great  pleasure  in  recommend- 
ing it.  As  an  exponent  of  the  midwifery  of  the 
present  day  it  has  no  superior  in  the  English  lan- 
guage.— Catiada  Lancet,  Jan.  1880. 

To  the  American  student  the  work  before  us 
must  prove  admirably  adapted.  Complete  in  all  its 
parts,  essentially  modern  in  its  teachings,  and  with 
demonstrations  noted  for  clearness  and  precision, 
it  will  gain  in  favor  and  be  recognized  as  a  work 
of  standard  merit.  The  work  cannot  fail  to  be 
popular  and  is  cordially  recommended. — N.  O. 
Med.  and  Surg.  Journ.,  March,  1880. 


S3HT1I,  J.  LEWIS,  31.  n., 

Clinical  Professor  of  Diseases  of  Children  in  the  Bellevue  Hospital  Medical  College,  N.  Y. 

A  Complete  Practical  Treatise  on  the  Diseases  of  Children.  Fifth 
edition,  thoroughly  revised  and  rewritten.  In  one  handsome  octavo  volume  of  836  pages, 
with  illustrations.  Cloth,  $4.50 ;  leather,  $5.50 ;  very  handsome  half  Russia,  raised  bands,  $6. 
This  is  one  of  the  best  books  on  the  subject  with    which  we  venture  to  say  will  be  a  favorable  one 


which  we  have  met  and  one  that  has  given  us 
satisfaction  on  every  occasion  on  which  we  have 
consulted  it,  either  as  to  diagnosis  or  treatment. 
It  is  now  in  its  fifth  edition  and  in  its  present  form 
is  a  very  adequate  representation  of  the  subject  it 
treats  of  as  at  present  understood.    The  important 


Dublin  Journal  of  Medical  Science,  March,  18S3. 

There  is  no  book  published  on  the  subjects  of 
which  this  one  treats  that  is  its  equal  in  value  to 
the  physician.  While  he  has  said  just  enough  to 
impart  the  information  desired  by  general  practi- 
tioners on  such  questions  as  etiology,  pathology, 


subject  of  infant  hygiene  is  fully  dealt  with  in  the  :  prognosis,  etc.,  he  has  devoted  more  attention  to 
early  portion  of  the  nook.  The  great  bulk  of  the  ,  the  diagnosis  and  treatment  of  the  ailments  which 
work  is  appropriately  devoted  to  the  diseases  of  he  so  accurately  describes ;  and  such  information 
infancy  and  childhood.  We  would  recommend  is  exactly  what  is  wanted  by  the  vast  majority  of 
any  one  in  need  of  information  on  the  subject  to  ,  "family  physicians." — Va.  Med.  Monthly,  Feb. i882. 
procure  the  work  and  form  his  own  opinion  on  it,  | 

KEATING,  JOHN  31.,  M.  &., 

Lecturer  on  the  Diseases  vf  Children  at  the  University  of  Pennsylvania,  etc. 

The  Mother's  Guide  in  the  Management  and  Feeding  of  Infants.    In 
one  handsome  12mo.  volume  of  118  pages.     Cloth,  $1.00. 

Works  like  this  one  will  aid  the  physician  im-  I  the  employment  of  a  wet-nurse,  about  the  proper 
mensely,  for  it  saves  the  time  he  is  constantly  giv-  food  for  a  nursing  mother,  about  the  tonic,  effects 
ing  his' patients  in  instructing  them  on  the  sub-  of  a  bath,  about  the  perambulator  versus ;the  nurses, 
jects  here  dwelt  upon  so  thoroughly  and  prae-  arms,  and  on  many  other  subjects  concerning 
tically.  Dr.  Keating  has  written  a  practical  book,  which  the  critic  might  say,  "surely  this  is  obvi- 
has  carefully  avoided  unnecessary  repetition,  ana  ous,"  but  which  experience  teaches  us  are  exactly 
successfully' instructed  the-  mother  in  such  details  the  thingsneeded  to  be  insisted  upon,  with  therich 
of  the  treatment  of  her  child  as  devolve  upon  her.  |  as  well  as  theyoor.— London  Lancet,  January,  28 1882. 
He  has  studiously  omitted  giving  prescriptions,  i  a  book  small  in  size,  written  in  pleasant  style,  in 
and  instructs  the  mother  when  to  call  upon  the  language  which  can  be  readily  understood  by  any 
doctor, as  his  duties  are  totally  distinct  from  hers,  mother,  and  eminently  practical  and  safe;  in  fact 
—American  Journal  of  Obstetrics,  I  (ctober,  1881.         ,  a  book  for  which  we  have  been  waiting  a  long 

Dr.  Keating  has  kept  clear  of  the  common  fault  time,  and  which  we  can  most  heartily  recommend 
of  works  of  this  sort,  viz.,  mixing  the  duties  of  to  mothers  as  the  book  on  this  subject. — New  York 
the  mother  with  those  proper  to  the  doctor.    There    M  lal  and  Obstetrical  Review,  Feb.  1882. 

is  the  ring  of  common  sense  in  the  remarks  about 

OWEN,  ED3IUJSTD,  31.  B.,  F.  JR.  C.  S., 

Surgeon  to  the  Children's  Hospital,  Oreat  Orrnond  St.,  London. 
Surgical  Diseases  of  Children.    In  one  12mo.  volume.    Preparing.    See  Series 
of  Clinical  Mammals,  page  3. 

WEST,  CHARLES,  31.  D., 

Physician  to  the  Hospital  for  Sick  Children,  London,  etc 

Lectures  on  the  Diseases  of  Infancy  and  Childhood.    Fifth  American 
from  6th  English  edition.   In  one  octavo  volume  of  686  pages.   Cloth,  $4.50 ;  leather,  $5.50. 

By  the  Same  Author. 

On  Some  Disorders  of  the  Nervous  System  in  Childhood.    In  one  small 
12mo.  volume  of  127  pages.     Cloth,  $1.00. 

CONDIE'S    PRACTICAL    TREATISE    ON    THE    I    vised  and  augmented.    In  one  octavo  volume  of 
DISEASES  OF  CHILDREN.    Sixth  edition,  re-    |    779  pages.    Cloth,  $5.25  ;  leather,  «6.25. 


Lea  Brothers  &  Co.'s  Publications — Med.  Jmis.,  Miscel. 


31 


TIDY,  CHARLES  MEYMOTT,  M.  B.,  F.  C.  S., 

Professor  of  Chemistry  and  of  Forensic  Medicine  and  Public  Health  at  the  London  Hospital,  etc. 

Legal  Medicine.  VOLUME  II.  Legitimacy  and  Paternity,  Pregnancy,  Abor- 
tion, Rape,  Indecent  Exposure,  Sodomy,  Bestiality,  Live  Birth,  Infanticide,  Asphyxia, 
Drowning,  Hanging,  Strangulation,  Suffocation.  Making  a  very  handsome  imperial  oc- 
tavo volume  of  529  pages.     Cloth,  $6.00;  leather,  $7.00. 

Volume  I.  Containing  664  imperial  octavo  pages,  with  two  beautiful  colored 
plates.     Cloth,  $6.00 ;  leather,  $7.00. 

The  satisfaction  expressed  with  the  first  portion  i  tables  of  eases  appended  to  each  division  of  the 
of  this  work  is  in  no  wise  lessened  by  a  perusal  of  subject,  must  have  cost  the  author  a  prodigious 
the  second  volume.  We  find  it  characterized  by  amount  of  labor  and  research,  but  they  constitute 
the  same  fulness  of  detail  and  clearness  of  ex-  one  of  the  most  valuable  features  of  the  book, 
■n  which  we  had  occasion  so  highly  to  com-  especially  for  reference  in  medico-legal  trials. — 
nif  ad  in  our  former  notice,  and  which  render  it  so  American  Journal  of  the  Medical  Sciences,  April,  1884. 
valuable    to    the   medical   jurist.      The    copious 


TAYLOR,  ALFRED  S.,  M.  &., 

Lecturer  on  Medical  Jurisprudence  and  Chemistry  in  Guy's  Hospital,  London. 

A  Manual  of  Medical  Jurisprudence.  Eighth  American  from  the  tenth  Lon- 
don edition,  thoroughly  revised  and  rewritten.  Edited  by  John  J.  Keese,  M.  D.,  Professor 
of  Medical  Jurisprudence  and  Toxicology  in  the  University  of  Pennsylvania.  In  one 
large  octavo  volume  of  937  pages,  with  70  illustrations.  Cloth,  $5.00 ;  leather,  $6.00 ;  half 
Russia,  raised  bands,  $6.50. 

only  have  to  seek  for  laudatory  terms. — American 
Journal  of  the  Medical  Sciences,  Jan.  1881. 

This  celebrated  work  has  been  the  standard  au- 
thority in  its  department  for  thirty-seven  years, 
both  in  England  and  America,  in  both  the  profes- 
sions which  it  concerns,  and  it  is  improbable  that 
it  will  be  superseded  in  many  vears.  The  work  is 
simply  indispensable  to  every  physician,  and  nearly 
so  to  every  liberally-educated  lawyer,  and  we 
heartily  commend  the  present  edition  to  both  pro- 
fessions.— Albany  Law  Journal,  March  2G,  1881. 


""-The  American  editions  of  this  standard  manual 
have  for  a  long  time  laid  claim  to  the  attention  of 
the  profession  in  this  country;  and  the  eighth 
comes  before  us  as  embodying  tne  latest  thoughts 
and  emendations  of  Dr.  Taylor  upon  the  subject 
to  which  he  devoted  his  life  with  an  assiduity  and 
success  which  made  him  facile  princeps  among 
English  writers  on  medical  jurisprudence.  Both 
the  author  and  the  book  have  made  a  mark  too 
deep  to  be  affected  by  criticism,  whether  it  be 
censure  or  praise.  In  this  case,  however,  we  should 


By  the  Same  Author. 

The  Principles  and  Practice  of  Medical  Jurisprudence.  Third  edition. 
In  two  handsome  octavo  volumes,  containing  1416  pages,  with  18S  illustrations.  Cloth,  $10; 
leather,  $12.     Just  ready. 


Fi>i  years  Dr.  Taylor  was  the  highest  authority 
in  England  upon  the  subject  to  which  he  gave 
1  attention.  His  experience  was  vast,  his 
judgment  excellent,  and  his  skill  beyond  cavil.  It 
is  therefore  well  that  the  work  of  one  who,  as  Dr. 
Stevenson  says,  had  an  "enormous  grasp  of  all 


matters  connected  with  the  subject,"  should  be 
brought  up  to  the  present  day  and  continued  in 
its  authoritative  position.  To  accomplish  this  re- 
sult Dr.  Stevenson  has  subjected  it  to  most  careful 
editing,  bringing  it  well  up  to  the  times. — Ameri- 
can Journal  of  the  Medical  Sciences,  Jan.  1884. 


By  the  Same  Author. 

Poisons  in  Belation  to  Medical  Jurisprudence  and  Medicine.  Third 
American,  from  the  third  and  revised  English  edition.  In  one  large  octavo  volume  of  788 
pages.     Cloth,  $5.50 ;  leather,  $6.50. 

FEFFER,  AUGUSTUS  J.,  31.  S.,  M.  B.,  F.  R.  C.  S., 

Medicine  at  the  University 
Forensic  Medicine.    In  one  pocket-size  12mo.  volume.    Preparing.    See  St '"lints' 
s  '■-,  page  3. 

LEA,  HENRY  C. 

Superstition  and  Force :  Essays  on  The  "Wager  of  Law,  The  Wager  of 
Battle,  The  Ordeal  and  Torture.  Third  revised  and  enlarged  edition.  In  one 
handsome  royal  12mo.  volume  of  652  pages.     Cloth,  $2.50. 


'.  aloable  work  La  in  reality  a  history  of  civ- 
ilization as  interpreted  by  the  progress  of  jurispru- 
dence. .    .    In  "Superstition  and  Force"  wel 
I  rarvey  of  the  long  period  intervening 

I  i  barbs         md  civilized  ei 

enment.    There  is  not  a  chapter  in  the  work  that 


should  not  be  most  carefully  studied  ;  and  however 
well  versed  the  reader  may  be  in  the  science  of 
jurisprudence,  he  will  find  much  in  Mr.  I.ea's  vol- 
*  which  he  was  previously  ignorant.  The 
book  is  a  valuable  addition  to  the  literature  of  so- 
cial science. —  Westminster  Pericw,  Jan.  1880. 


By  the  Same  Author. 
Studies  in  Church  History.    The  Bise  of  the  Temporal  Power— Ben- 


efit of  Clergy — Excommunication 
octavo  volume  of  605  pages.     Cloth,  $! 

Theauthor  is  pre-eminently  a  scholar.    He  takes 
up  every  topic  allied  with  the  leadii 
traces  it  out  to  the  minutest  detail  with  a  wealth 
of  knowledge  and  impartiality  of  treatment  that 

compel  admiration.    The  amount  of  information     cisenese  and    freedom    from    prejudice, 
compressed  into  the  book  is  extraordinary.    In  no     Traveller,  Mav  3,  1883. 
other  single  volume  is  the  developn  cut  •>!"  the 


lition.     In  one  very  handsome  royal 
-  tdy. 

primitive  church  traced  with  so  much  clearness, 
and  with  so  definite  a  perception  of  complex  or 
conflict]  The  fifty  pages  on  the  growth 

of  the  papacy,  for  instance,  are  admirable  for  con- 

Boston 


Allen's  Anatomy  .... 

American  Journal  of  the  Medical  Sciences 
American  System  of  Gynaecology    . 
American  System  of  Practical  Medicine 
•Ash  ery     .... 

A&hwell  on  I  Women 

AttSeld'8  Chemistry      .... 
Ball  on  the  Rectum  and  Anus 
Barker's  <  ibstetrii  saj  s, 

Barlow's  I'v  Heine 

Barnes'  Midwifery 
*Barnes  on  Diseases  of  Women 
Barn—  Obstetric  Medicine 

Bartholow  on  Electricity 

:n  on  Elena!  1  diseases    . 
Bells  Comparative  Physiology  and  Anatomy 
Bellamy's  Operative  Surgery 
Bellamy's  Surgical  Anatomy 
Blandford  on  Insanity 
Bloxam's  Chemistry     . 
Bowman's  Practical  Chemistry 
*Bristowe's  Practice  of  Medicine    . 
Broadbent  on  the  Pulse 

Browne  nn  the  Ophthalmoscope 

Browne  on  the  Throat 

Bruce's  Materia  Medicaand  Therapeutics 

Brunton's  Matei  la  Medica  and  Therapeutics 

Bryant  on  the  Breast    .... 

•Bryant's  Practice  of  Surgery 

*Bumstead  on  Venereal  Diseases    . 

♦Burnett  on  the  Ear       .... 

Butlin  on  ti.e  I  ongue    .... 

Carpenter  on  \i.nse  of  Alcohol 

♦Carpenter's  Human  Physiology    . 

Carter  on  the  Eye  .... 

Century  of  American  Medicine 

Chambers  on  Diet  and  Regimen 

Charles'  Physiological  and  Pathological  Chem 

Churchill  on  Puerperal  Fever 

Clarke  and  Lock  wood's  Dissectors'  Manual 

Classen's  Quantitative  Analysis 

Cleland's  Dissector 

Clouston  on  Insanity 

Clowes'  Practical  Chemistry 

Coats'  Pathology  .... 

Cohen  on  the  Throat      .... 

Coleman's  Dental  Surgery 

Condie  on  Diseases  of  Children 

Cooper's  Lectures  on  Surgery 

Cornil  on  Syphilis         . 

•Cornil  and  Ranvier's  Pathological  Histology 

Cullerier's  Atlas  ol  Venereal  Diseases 

Ournow'S  Medical  Anatomy 

Dalton  on  the  Circulation       .        , . 

•Dalton's  HumanPhysiology 

Dalton's  Topographical  Anatomy  of  the  Brain 

Davis'  Clinical  Lectures 

Draper's  Medical  Physics 

Drum's  Modern  Surgery 

Duncan  on  Diseases  of  Women 

•Dunglison'8  Medical  Dictionary    . 

Edis  on  Diseases  of  Won. en    . 

Ellis'  Demonstrations  of  Anatomy 

Emmet's  Gynaecology 

•Erichsen's  System  of  Surgery 

Esmarch's  Early  Aid  in  Injuries  and  Accid'ts 

Farquharson's  Therapeutics  and  Mat.  Med. 

Fenwick's  Medical  Diagnosis 

Finlayson's  Clinical  Diagnosis 

Flint  on  Auscultation  and  Percussion 

Flint  on  Phthisis  .... 

Elint  on  Physical  Exploration  of  the  Lungs 

Flint  on  Respiratory  Organs 

Flint  on  the  Heart 

♦Flint's  Clinical  Medicine 

Flint's  Essays       .  .  . 

♦Flint's  Practice  of  Medicine 

Folsom's  Daws  of  U.  Si  on  Custody  of  Insane 

Foster's  Physiology      .  . 

♦Fothergill's  Handbook  of  Treatment     . 

Fownes'  Elementary  Chemistry 

Fox  on  Diseases  of  the  Skin  . 

Franklanil  and  Japp's  Inorganic  Chemistry 

Fuller  on  the  Lungs  and  Air  Passages      . 

Gallowaj  'a  Analysis       .... 

Gibney's  Orthopaedic  Surgery 

Gibson's  sin  l  .... 

Gluge's  Pathological  Histology,  by  Leidy 
Gould's  Surgical  Diagnosis     . 
•Gray's  Anatomy  ...  .       . 

Greene's  Medical  Chemistry  . 

Green's  Pathology  and  Morbid  Anatomy 

Griilith's  Universal  Formulary 

Gross  'iii  Foreign  Bodies  in  Air-Passages 

II  i- and  Sterility     . 
Gross  on  Urinary  Organs 
•Gross'  System  ofSurgery 
Habershon  on  the  Abdomen 
•Hamilton  on  Fractures  and  Dislocations 
Hamilton  on  Nervous  Diseases 

Hartahorne's  Anat y  and  Physiology  . 

Ha  it  si  i  nine's  Conspectus  of  the  Med.  Sciences 
Hartshorne's  Essentials  of  Medicine 
Hermann's  Experimental  Pharmacology 
Hill  "I,  Syphilis  ..... 
Hillier's  Handbook  of  Skin  Diseases 
Hoblyn's  Medical  Dictionary 
Hodge  on  Women  .... 

Hodge's  obstetrics         .... 


6  Hoffmann  and  Power's  Chemical  Analysis 

:;  Holden's  Landmarks    .... 

27  Holland's  Medical  Notes  and  Reflections 

15  Holmes' System  of  Surgery 

l'ii  Horner's  Anatomy  and  Histology 

28  Hudson  on  Fever 

ii  Hutchinson  on  Syphilis 

21  Hyde  on  the  Diseases  of  the  Skin    . 

29  Jones  (C.  Handfield)  on  Nervous 

17  Juler'a  <  ij  ience  and  Practice 

29  Keating  nil    Infants 

27  King's  Manual  of  Obstetrics    . 
29  Klein's  Histology 

17  l.andis  on  Lai 

21  La  Roche  on  Pneumonia,  Malaria,  etc.    . 

3  7  La  Roche  on  Yellow  Fever    . 

'■>.  20  Laiin-i.ee  and  Moon's  I  Iphtbalmic  Surgery 

6  Lawsnn  on  llie  Eye,  Orbit  and  Eyelid 

19  Lea's  Studies  in  Church  History     . 

9  Lea's  Superstition  and  Force 

9  Lee  on  syphilis 

M  Lehmann  8  Chemical  Physiology    . 

;;.  16       Leishman's  Midwifery  '       .  . 

23  Lucas  on  Diseases  of  the  Urethra   . 

is  Ludlow's  Manual  of  Examinations 

1 1  Lyons  On  Fever    ..... 

n  Mi  ilc  Materia  Medica  . 

3,'Ji  Marsh  on  the  Joints 

21  May  on  Diseases  of  Women  . 

25  Ml  'ileal  News       .  ... 

'JI  Meigs  on  Childbed  Fever 

8,21  Miller's  Practice  of  Surgery   . 

s  Miller's  Principles  of  Surgery 

s  Mitchell's  Nervous  Diseases'of  Women    . 

23  Morris  on  Diseases  of  the  Kidneys 

l-i  Morris  on  Skin  Diseases  . 

17  Neill  and  Smith's  Compendium  of  Med.  Sci. 
10  NetUeshipon  Diseases  of  the  Eye  . 

28  Owen  on  Diseases  of  Children 

6  *Parrish's  Practical  Pharmacy 

10  Parry  on  Extra-Uterine  Pregnancy 

5  Parvin's  Midwifery        .... 

P'  Pavy  on  Digestion  and  its  Disorders 

in  Pepper's  Forensic  Medicine  . 
Pepper's  Surgical  Pathology 
Pick  on  Fractures  and  Dislocations 
Pirrie's  System  of  Surgery 
Playl'air  on  Nerve  Prostration  and  Hysteria 
•Playfair's  Midwifery   .  . 

25  Politzer  on  the  Ear  and  its  Diseases 

13  Power's  Human  Physiology  . 
Rain's  Clinical  Chemistry  '     . 

3,  ii  Ramsbotham  on  Parturition 

7  Remsen's  Theoretical  Chemistry    . 

8  i  ^Reynolds'  System  of  Medicine 

7  Richardson's  Preventive  Medicine 

16  Roberts  on  Urinary  Diseases 

7  Roberts'  Principles  and  Practice  of  Surgery 

21  Kobertson's  Physiological  Physics 

25  Rodwell's  Dictionary  of  Science 
-1  Boss  on  Nervous  Diseases 

27  Sargent's  Minor  and  Military  Surgery 

7  Savage  on  Insanity,  including  Hysteria  . 

28  Schafer's  Essentials  of  Histology, 
21  Schafer's  Histology 

21  Sehreiber  on  Massage   . 

12  Seiler  on  the  Throat,  Nose  and  Naso-Pharynx 
hi  Series  of  Clinical  Manuals 

16  Simon's  Manual  of  Chemistry 

18  I  Skey's  Operative  Surgery 

18  I  Slade  on  Diphtheria      .... 

18  smith  i  Edward  i  on  Consumption    . 

18  Smith  (H.  H.)  and  Horner's  Anatomical  Atlas 

18  *Smith  tJ.  Lewis)  on  Children 
lf>  I  Stllle  on  Cholera  .... 
16  *Stille  tt  Maisch's  National  Dispensatory 

14  *sij He's  Therapeutics  and  Materia  Medica 

19  Slimson  on  Fractures   .... 

8  Stinason's  Operative  Surgery 

16  Stokes  on  Fever  ..... 

8  Students' Series  of  Manuals    . 

26  Sturges'  Clinical  Medicine 

9  Tanner  on  Signs  and  Diseases  of  Pregnancy 
Is  Tanner's  Manual  of  Clinical  Medicine 

plor  on  Poisons  .... 

20  *Tayior's  Medical  Jurisprudence    . 

20  Taylor's  Pi  in.  and  Prac.  of  Med.  Jurisprudence 

rhomas  on  Diseases  of  Women 

3, '20  Thompson  on  Stricture 

5  Thompson  on  Urinary  Organs 

in  Tidy's  Legal  Medicine. 

13  Todd  on  Acute  Diseases 

11  Treves'  Applied  Anatomy 

18  Treves  on  Intestinal  Obstruction    . 

25  Tukenn  the  Influence  of  Mind  on  the  Body 

21  Walshe  on  the  Heart    .... 
20  Watson's  Practice  of  Physic  . 

17  *\\'i-Us  on  i in-  Eye        .'       . 
23  West  on  Diseases  of  Childhood 
pi  Weston  Diseases  of  Women 

ii  Wesl  on  Nervous  Disorders  in  Childhood 

:;  Williams  on  Consumption 

l-i  Wilsons  Handbook  of  Cutaneous  Medicine 

n  Wilson's  Human  Anatomy   . 

25  Winckel  on  Pathol,  and  Treatment  of  Childbed 

26  Wfthler's  Organic  Chemistry 
•)  Woodbead's  Practical  Pathology    . 

28  Year-Book  of  Treatment 
28 


Books  marked  *  are  also  bound  in  half  Russia. 


LEA    BROTHERS    &    CO.,    Philadelphia. 


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